Psychological preparation and postoperative outcomes for adults undergoing surgery under general anaesthesia

Rachael Powell; Neil W Scott; Anne Manyande; Julie Bruce; Claus Vögele; Lucie MT Byrne‐Davis; Mary Unsworth; Christian Osmer; Marie Johnston

doi:10.1002/14651858.CD008646.pub2

. 2016 May 26;2016(5):CD008646. doi: 10.1002/14651858.CD008646.pub2

Psychological preparation and postoperative outcomes for adults undergoing surgery under general anaesthesia

Rachael Powell ^1,^✉, Neil W Scott ², Anne Manyande ³, Julie Bruce ⁴, Claus Vögele ⁵, Lucie MT Byrne‐Davis ⁶, Mary Unsworth ⁷, Christian Osmer ⁸, Marie Johnston ⁹

Editor: Cochrane Anaesthesia Group

PMCID: PMC8687603 PMID: 27228096

Abstract

Background

In a review and meta‐analysis conducted in 1993, psychological preparation was found to be beneficial for a range of outcome variables including pain, behavioural recovery, length of stay and negative affect. Since this review, more detailed bibliographic searching has become possible, additional studies testing psychological preparation for surgery have been completed and hospital procedures have changed. The present review examines whether psychological preparation (procedural information, sensory information, cognitive intervention, relaxation, hypnosis and emotion‐focused intervention) has impact on the outcomes of postoperative pain, behavioural recovery, length of stay and negative affect.

Objectives

To review the effects of psychological preparation on postoperative outcomes in adults undergoing elective surgery under general anaesthetic.

Search methods

We searched the Cochrane Register of Controlled Trials (CENTRAL 2014, Issue 5), MEDLINE (OVID SP) (1950 to May 2014), EMBASE (OVID SP) (1982 to May 2014), PsycINFO (OVID SP) (1982 to May 2014), CINAHL (EBESCOhost) (1980 to May 2014), Dissertation Abstracts (to May 2014) and Web of Science (1946 to May 2014). We searched reference lists of relevant studies and contacted authors to identify unpublished studies. We reran the searches in July 2015 and placed the 38 studies of interest in the `awaiting classification' section of this review.

Selection criteria

We included randomized controlled trials of adult participants (aged 16 or older) undergoing elective surgery under general anaesthesia. We excluded studies focusing on patient groups with clinically diagnosed psychological morbidity. We did not limit the search by language or publication status. We included studies testing a preoperative psychological intervention that included at least one of these seven techniques: procedural information; sensory information; behavioural instruction; cognitive intervention; relaxation techniques; hypnosis; emotion‐focused intervention. We included studies that examined any one of our postoperative outcome measures (pain, behavioural recovery, length of stay, negative affect) within one month post‐surgery.

Data collection and analysis

One author checked titles and abstracts to exclude obviously irrelevant studies. We obtained full reports of apparently relevant studies; two authors fully screened these. Two authors independently extracted data and resolved discrepancies by discussion.

Where possible we used random‐effects meta‐analyses to combine the results from individual studies. For length of stay we pooled mean differences. For pain and negative affect we used a standardized effect size (the standardized mean difference (SMD), or Hedges' g) to combine data from different outcome measures. If data were not available in a form suitable for meta‐analysis we performed a narrative review.

Main results

Searches identified 5116 unique papers; we retrieved 827 for full screening. In this review, we included 105 studies from 115 papers, in which 10,302 participants were randomized. Mainly as a result of updating the search in July 2015, 38 papers are awaiting classification. Sixty‐one of the 105 studies measured the outcome pain, 14 behavioural recovery, 58 length of stay and 49 negative affect. Participants underwent a wide range of surgical procedures, and a range of psychological components were used in interventions, frequently in combination. In the 105 studies, appropriate data were provided for the meta‐analysis of 38 studies measuring the outcome postoperative pain (2713 participants), 36 for length of stay (3313 participants) and 31 for negative affect (2496 participants). We narratively reviewed the remaining studies (including the 14 studies with 1441 participants addressing behavioural recovery). When pooling the results for all types of intervention there was low quality evidence that psychological preparation techniques were associated with lower postoperative pain (SMD ‐0.20, 95% confidence interval (CI) ‐0.35 to ‐0.06), length of stay (mean difference ‐0.52 days, 95% CI ‐0.82 to ‐0.22) and negative affect (SMD ‐0.35, 95% CI ‐0.54 to ‐0.16) compared with controls. Results tended to be similar for all categories of intervention, although there was no evidence that behavioural instruction reduced the outcome pain. However, caution must be exercised when interpreting the results because of heterogeneity in the types of surgery, interventions and outcomes. Narratively reviewed evidence for the outcome behavioural recovery provided very low quality evidence that psychological preparation, in particular behavioural instruction, may have potential to improve behavioural recovery outcomes, but no clear conclusions could be reached.

Generally, the evidence suffered from poor reporting, meaning that few studies could be classified as having low risk of bias. Overall,we rated the quality of evidence for each outcome as ‘low’ because of the high level of heterogeneity in meta‐analysed studies and the unclear risk of bias. In addition, for the outcome behavioural recovery, too few studies used robust measures and reported suitable data for meta‐analysis, so we rated the quality of evidence as `very low'.

Authors' conclusions

The evidence suggested that psychological preparation may be beneficial for the outcomes postoperative pain, behavioural recovery, negative affect and length of stay, and is unlikely to be harmful. However, at present, the strength of evidence is insufficient to reach firm conclusions on the role of psychological preparation for surgery. Further analyses are needed to explore the heterogeneity in the data, to identify more specifically when intervention techniques are of benefit. As the current evidence quality is low or very low, there is a need for well‐conducted and clearly reported research.

Plain language summary

The effect of psychological preparation on pain, behavioural recovery, negative emotion and length of stay after surgery

Background

The way people think and feel before surgery can affect how they feel and what they do after surgery. For example, research shows that people who feel more anxious before their surgery experience more pain after it. A review conducted in 1993 looked at the impact of psychological preparation on outcomes after surgery. The term `psychological preparation' includes a range of techniques that aim to change what people think, how they feel or what they do. This 1993 review found that psychological preparation techniques reduced pain after surgery, improved behavioural recovery (how quickly people return to activities), decreased length of stay in hospital and reduced negative emotion (e.g. feelings of anxiety or depression). We aimed to carry out an up‐to‐date review using Cochrane methodology to learn whether there are helpful (or harmful) effects of psychological preparation for people undergoing surgery, and which outcomes (pain after surgery, behavioural recovery, negative emotion or length of stay) are improved.

Study characteristics

We included studies of adults who received planned surgery with general anaesthesia. We looked at seven psychological preparation techniques: procedural information (information about what, when and how processes will happen); sensory information (what the experience will feel like and what other sensations they may have, e.g. taste, smell); behavioural instruction (telling patients what they need to do); cognitive intervention (techniques that aim to change how people think); relaxation techniques; hypnosis; and emotion‐focused interventions (techniques that aim to help people to manage their feelings). The psychological preparation had to be delivered before surgery for the study to be included in the review. We included studies that looked at the effect of psychological preparation on pain, behavioural recovery, length of stay and negative emotion after surgery (within one month). Studies were included in the review up to the search date of 4 May 2014. We updated the search on 7 July 2015 and will incorporate the 38 studies found in this later search when the review is updated. We included 105 studies from 115 papers, with 10,302 participants taking part. Sixty‐one studies measured the outcome pain, 14 behavioural recovery, 58 length of stay and 49 negative emotion. In accordance with the review protocol, we did not record details about funding sources.

Key results

In this review we included 105 studies, which were reported in 115 papers. A total of 10,302 participants were randomized in these studies. For pain, length of stay and negative emotion we combined numerical findings from the studies. We found that psychological preparation before surgery seemed to reduce pain and negative emotion after the operation and may reduce the time spent in hospital by around half a day but the quality of the evidence was low. Also, the studies used many different psychological preparation techniques (often in different combinations) so it was not possible to discover which techniques were better. We could not statistically combine numerical findings for behavioural recovery because few studies provided sufficient details and studies used different ways of measuring how quickly people returned to usual activities. In reviewing the studies, we found that psychological preparation, in particular behavioural instruction, may have the potential to improve behavioural recovery. However, the quality of this evidence was very low. We looked at the effect of psychological preparation on pain, behavioural recovery, length of stay and negative emotion in this review and did not find evidence to suggest that psychological preparation might lead to harm in these outcomes. However, as we did not look at other outcomes it is possible that we did not identify potential harm.

Quality of the evidence

Many studies were poorly reported, so we could not be confident that findings were reliable. For this reason and because of the large variation in psychological techniques, types of surgery and measures used, we graded the quality of the evidence as `low' for the outcomes pain, negative emotion and length of stay; we cannot be confident that these techniques help patients to recover from surgery. For behavioural recovery, we further downgraded the quality of the evidence to `very low' because of problems with measurement and reporting of the outcome.

Summary of findings

Background

Many people experience anxiety and negative cognitions when approaching surgery (Mathews 1981). There is good evidence that how people think and feel before surgery affects their outcomes after surgery. Negative psychological factors such as anxiety, depression and catastrophizing have been found to predict postoperative pain (Arpino 2004; Bruce 2012; Granot 2005; Munafó 2001). Catastrophizing has been defined as "an exaggerated negative orientation toward noxious stimuli" (Sullivan 1995).

A range of mechanisms exist by which psychological variables could affect recovery after surgery. First, negative emotions can enhance pain sensations (Rainville 2005; van Middendorp 2010). Second, cognitions and emotions influence behaviour (for example doing physiotherapy exercises, taking analgesics) and are likely to influence pain and return to usual activities. Third, stress has been linked to the slower healing of wounds through psychoneuroimmunological mechanisms (mechanisms whereby psychology interacts with the nervous and immune systems) (Maple 2015; Marucha 1998; Walburn 2009). It is therefore likely that psychological interventions that reduce negative emotions such as anxiety, worry about surgery and perceptions of stress, or that change patients' recovery‐related behaviour, may lead to positive postoperative outcomes.

Psychological preparation for surgery has been demonstrated to improve outcomes. In a review and meta‐analysis (Johnston 1993), psychological preparation was found to be beneficial for a range of outcome variables that included negative affect, pain, pain medication, length of hospital stay, behavioural recovery, clinical recovery, physiological indices and satisfaction.

Since the 1993 review (Johnston 1993), this research field has continued to develop. Standards of conducting randomized controlled trials have improved, technology has advanced to permit more detailed bibliographic searching and new studies testing psychological preparation procedures have been published. The present review tested, using modern review techniques, analysis methods and a larger research base, a) whether there is evidence for beneficial (or harmful) effects of psychological preparation for surgery, and b) which outcomes of pain, behavioural recovery, length of stay and negative affect are improved (or worsened) following preparation.

Description of the condition

Surgery is carried out for a range of health conditions either as a diagnostic or treatment intervention. While surgery may lead to health improvements, it also negatively impacts on a range of health outcomes including pain, activity limitations and anxiety, at least in the short term (Johnston 1980).

Elective surgery differs from emergency surgery in that patients have time to prepare themselves and to be prepared for surgery. Preparation for emergency surgery is much more difficult to provide in a controlled manner and the effectiveness of such interventions is likely to differ because of that difference in context. Thus, emergency surgery should be considered separately and we only included participants undergoing elective surgery in this review.

Different psychological threats and coping mechanisms can be involved for the patient depending on whether procedures are undertaken using general anaesthetic or local anaesthetic. For example in some procedures that are performed under local anaesthetic the patients are required to be actively involved, and so effective preparation will have different components compared with preparation for a procedure where the patient is unconscious. Therefore, following Johnston 1993, we only included procedures involving general anaesthetic.

Description of the intervention

Psychological preparation incorporates a range of strategies designed to influence how a person feels, thinks or acts (emotions, cognitions or behaviours). Johnston 1993 found that the following types of intervention benefited patients, on at least one postoperative outcome: procedural information, sensory information, behavioural instruction, cognitive intervention, relaxation techniques, hypnosis and emotion‐focused interventions.

Procedural information

Procedural information describes the process the patient will undergo in terms of what will happen, when it will happen and how it will happen.

Sensory information

Sensory information describes the experiential aspects of the procedure, that is, what it will feel like and any other relevant sensations (for example taste, smell).

Behavioural instruction

Behavioural instruction consists of telling patients what they should do to facilitate either the procedure or their recovery from the procedure (Mathews 1984). For example a patient could be told how to use equipment, such as a patient‐controlled analgesia pump.

Cognitive interventions

Cognitive interventions aim to change how an individual thinks, especially about negative aspects of the procedure. Cognitive techniques include cognitive reframing and distraction. Cognitive reframing involves developing a different perspective that enables a positive or neutral rather than negative thought, for example focusing on the number of people who do well after a surgical procedure rather than the number who fare badly. Distraction leads to focusing thoughts on other things (and could include relaxation).

Relaxation techniques

These involve "systematic instruction in physical and cognitive strategies to reduce sympathetic arousal, and to increase muscle relaxation and a feeling of calm" (Michie 2008). Relaxation techniques can be used before surgery to reduce tension and anxiety and include progressive muscle relaxation (where each muscle group is tensed and then relaxed), simple relaxation (each muscle group is relaxed in turn), breathing techniques (for example the practice of diaphragmatic breathing) and guided imagery (for example imagining a pleasant, relaxing environment).

Hypnosis

A range of procedures are used for hypnotic induction, including suggestions to relax. During hypnosis "one person (the subject) is guided by another (the hypnotist) to respond to suggestions for changes in subjective experience, alterations in perception, sensation, emotion, thought or behavior" (APA 2005).

Emotion‐focused interventions

Emotion‐focused interventions aim to enable the person to regulate or manage their feelings or emotions. Emotion‐focused methods include: enabling the discussion, expression or acceptance of emotions; facilitating contextualization (putting emotions into context, e.g. of life, relationships, past experiences); and enabling the understanding of emotions (e.g. giving them meaning). In this review, if the focus of the intervention was to change how someone thinks, we coded it as a ‘cognitive intervention’.

How the intervention might work

Studies have shown that psychological preparation for surgery can have a beneficial effect upon a range of postoperative outcomes (Johnston 1993). Likely mechanisms for these processes vary depending upon the intervention used. Some intervention types focus on reducing negative emotions, such as anxiety, and negative thought processes. Providing procedural information is expected to reduce anxiety because it helps the patient to know what to expect when they undergo surgery. It reduces uncertainty, and ensures that concern is not caused by events that are part of normal hospital procedures (Ridgeway 1982). Similarly to providing procedural information, providing sensory information is expected to reduce anxiety by reducing the discrepancy between the sensation expected by the patient and the sensation actually experienced (Johnson 1973). For example, if a patient expects to experience discomfort after surgery in a particular bodily location, when this discomfort is experienced it is understood as being part of the normal surgical experience rather than an indication that something has gone wrong. Cognitive interventions aim to reduce negative emotions and thoughts related to the surgical process by either changing negative thoughts or refocusing attention elsewhere, and emotion‐focused interventions target an individual's emotions directly. Relaxation and hypnosis interventions aim to make an individual feel more relaxed, both psychologically and physiologically, and may effectively act as distraction techniques, so reducing both negative emotions and negative thoughts. As noted earlier, negative thoughts and emotions influence wound healing (Kiecolt‐Glaser 1998), perceptions of pain and also behaviour. Finally, behavioural instruction aims to directly influence behaviours that are important in enabling the surgical procedure to go well and to enhance recovery, for example teaching people how to manage their own analgesia, or instructing them as to when they should return to usual activities for optimal recovery.

Why it is important to do this review

Improving outcomes after surgery has a range of benefits both for the individual and for the healthcare service. Individuals will benefit from reduced postoperative pain and a quicker return to activity. Economic benefits include shorter stays in hospital, reduced use of pain medication and quicker return to work.

Objectives

To review the effects of psychological preparation on postoperative outcomes in adults undergoing elective surgery under general anaesthetic.

Methods

Criteria for considering studies for this review

Types of studies

We included both published and unpublished randomized controlled trials (RCTs). We excluded quasi‐randomized trials. We included, and narratively described, cluster‐randomized controlled trials but did not include them in the meta‐analyses.

Types of participants

We included studies with adult participants (aged 16 years or older) undergoing elective surgery under general anaesthesia. If information about anaesthesia was not provided we contacted the study authors for confirmation. If no response was received, we took advice from a clinician (either a surgeon or anaesthesiologist) who assessed whether that type of surgery would usually be performed under general anaesthesia. We included or excluded studies on this basis. Some surgical procedures are carried out under either general or local anaesthesia (for example inguinal hernia repair surgery). We included studies containing a mixture of participants undergoing general and local anaesthesia but excluded studies where all participants underwent, or were expected to have undergone, local (or no) anaesthesia (with or without sedation).

We included studies of people who have received premedicative sedative prior to general anaesthesia. Different issues are encountered with children undergoing surgery (for example their developmental stage) and different psychological techniques are used (Johnston 1993). Studies tend to focus either on adults or children. We excluded participants aged less than 16 years from this current review.

We excluded studies focusing on patient groups with clinically diagnosed psychological morbidity. However, we did not exclude studies that included participants with mental disorders or subclinical symptoms co‐existing with the condition that led to the operation.

Types of interventions

Psychological preparation, including:

procedural information;
sensory information;
behavioural instruction;
cognitive interventions;
relaxation techniques;
hypnosis;
emotion‐focused interventions.

‘Psychological preparation’ was defined as interventions where the intervention was entirely provided before surgery (this preparation could include, for example, instructions for the participant for after surgery, but the implementation of the intervention had to be pre‐surgery). We were interested in the psychological content of the intervention in this review rather than how it is delivered. There are studies that compare different formats (e.g. leaflet versus video) or timings, but the actual content of the intervention is the same. We excluded these papers. Where the control group also received an element of preoperative preparation (for example, procedural information), the intervention group was required to receive that element beyond that received by the control group (for example, more detailed procedural information, or procedural information about additional aspects of surgery) to be considered as an `intervention'.

Types of outcome measures

We included studies that collected data on two primary and two secondary outcomes. We only included outcomes measured within 30 days/one month post‐surgery. We excluded studies that did not measure these outcomes for pragmatic reasons: because of the size of the review and available research team resources, including all studies measuring any outcome was not manageable (see Differences between protocol and review). Where repeated measurements of outcomes were taken postoperatively, we used the earliest measure for the main meta‐analysis. This is because, while the longest follow‐up is important for longer‐term recovery, it was likely that most studies would include short‐term outcome data but only a few would also include longer time frames.

Primary outcomes

1. Postoperative pain

1a. Postoperative pain intensity: there are a range of well‐used measures for pain and some studies report pain as an outcome using more than one measure. We extracted all reported postoperative pain outcomes from each study.

We used the following hierarchy when deciding which postoperative pain measure to use in the meta‐analysis:

the pre‐specified postoperative pain outcome (if given);
a visual analogue scale (VAS), for example from 0 to 100 (or 0 to 10);
McGill Pain Questionnaire (MPQ) (Melzack 1975) intensity rating, Present Pain Intensity;
other MPQ ratings: i) Pain Rating Index (weighted or unweighted), ii) Number of Words Counted;
Short Form‐36 (SF‐36) pain (Ware 2000);
Nottingham Health Profile pain (Hunt 1983);
other pain intensity scale.

We analysed pain at rest over pain at movement; moving in bed over pain when standing or walking; average pain over pain at rest or current pain; current pain over retrospective pain; worst pain over least pain or current pain. We prioritized sensory over affective measures, and self‐report over observer‐report pain measures.

1b. Proportion of participants in pain postoperatively as defined by the authors of included studies.

2. Behavioural recovery* (defined as: resumption of performance of tasks and activities).

Where multiple measures were used, we made the following decisions in prioritizing measures:

SF‐36 physical function (Ware 2000);
Nottingham Health Profile: Physical mobility (Hunt 1983);
Barthel Index (Mahoney 1965);
Western Ontario and McMaster Osteoarthritis Index (WOMAC) functional status (Bellamy 1988).

Secondary outcomes

1 Negative affect*

Where multiple measures were used, we used the following hierarchy when deciding which measures to use in meta‐analysis:

State Trait Anxiety Inventory (STAI) state (Spielberger 1983);
STAI trait (Spielberger 1983);
Profile of Mood States (POMS) tension/anxiety (McNair 1971);
POMS global (McNair 1971);
Multiple Affect Adjective Check List (MAACL) Anxiety/fear (Zuckerman 1965);
MAACL total (Zuckerman 1965);
Mood Adjective Checklist (MACL) (Radloff 1968);
Hospital Anxiety and Depression Scale (HADS) anxiety (Zigmond 1983);
HADS depression (Zigmond 1983);
General Health Questionnaire 28 (Goldberg 1978);
Perceived Stress Scale (Cohen 1983);
Hospital Anxiety Scale (Lucente 1972);
SF‐36 mental health (Ware 2000);
Nottingham Health Profile: Emotional Reaction (Hunt 1983);
Psychologic Global Well‐being Scale (Dupuy 1984);
BSKE (EWL) (Befindlichkeitsskalierung durch Kategorien und Eigenschaftswörter): Psychological Global Well‐being/mood (Janke 1994);
Structured interview: Modified Present State Examination schedule (Tait 1982) and the Diagnostic and Statistical Manual of Mental Disorders, third edition (DSM‐III) (APA 1980).

2. Length of stay in hospital (days)

*For the outcomes of behavioural recovery and negative affect we included only studies that used measures with published psychometric properties, including reliability and validity. We recorded the timing of outcome assessment.

Search methods for identification of studies

Electronic searches

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2014, Issue 5); MEDLINE (Ovid SP) (1950 to 4 May 2014); EMBASE (Ovid SP) (1982 to 4 May 2014); PsycINFO (Ovid SP) (1982 to 4 May 2014); CINAHL (EBSCOhost) (1980 to 4 May 2014); Dissertation Abstracts and ISI Web of Science (1946 to 4 May 2014). We reran the search on 7 July 2015; the additional studies identified (after screening titles and abstracts to exclude any obviously irrelevant studies) are listed under Characteristics of studies awaiting classification.

We used the following subject search terms for searching the databases:

`psychological preparat*', education, information, instruction, cognitive interven*, `cognitive behavio?ral therapy', `cognitive therapy', `behavio*ral therapy', hypnosis, relaxation, guided imagery, surgery, operat*, surgical procedure, general an*esthetic, elective surgery, cholecystectomy, hysterectomy, hernia repair, herniorrhaphy, hernioplasty, joint replacement surgery, arthroplasty.

We combined our subject search terms with the Cochrane highly sensitive search strategy for identifying RCTs as suggested in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). The full search strategies are provided in the Appendices (Appendix 1 for CENTRAL, The Cochrane Library; Appendix 2 for MEDLINE (OvidSP); Appendix 3 for EMBASE (OvidSP); Appendix 4 for CINAHL (EBSCOhost); Appendix 5 for ISI Web of Science).

Searching other resources

We searched the reference lists of relevant papers for additional sources where references were provided in the English language. We contacted the authors of relevant studies to identify unpublished studies and dissertations.

We did not limit the search by language or publication status. Where papers were in a non‐English language, we asked a speaker of that language to screen the paper. A member of the review team went over the screening, checking each decision with the screener's description of what happened in the paper. Where the paper was deemed to fit the review criteria, if a member of the review team spoke the language, that individual extracted the data, with a second member of the review team (RP) then checking, by discussion with the first extractor, that decisions made and data extracted were correct. Where no member of the review team spoke the language of the paper, we gained English translations and extracted data in the same way as for English language papers.

Data collection and analysis

Selection of studies

One review author (RP) checked titles and abstracts of retrieved studies to exclude obviously irrelevant reports. A small, random sample was double‐checked by a second researcher (research assistant Yvonne Cooper, or authors MU and JB). Where the title and abstract indicated that a paper had the potential to fit inclusion criteria, copies of the trial were independently assessed for inclusion by two researchers (RP and one other member of the team: research assistant Louise Pike or authors MU, AM, CV, JB, NS, MJ or LBD). We resolved any disagreements by discussion with a third researcher (a member of the authorship team who had not assessed the paper).

Data extraction and management

Two review authors (RP and either MU, AM, JB, CV, MJ, JB, NS or research assistant Louise Pike) independently carried out data extraction using a data extraction form (see Appendix 6). We resolved any disagreement by discussing the matter with a third author (an author who had not previously extracted data from that paper). We extracted the following data:

Study participants: age, gender, total number of participants, location, setting, surgery type.
Study methods: study design, study duration.
Interventions: theoretical nature of intervention, number of intervention groups, specific intervention, intervention details (including delivery method), integrity of intervention, timing of intervention, control groups, usual care description, adherence to intervention and control, attrition rate, loss to follow‐up rate.
Outcomes: outcomes and time points a) collected, and b) reported; outcome definition, author's definition of outcome; measurement tool details (including, for example, upper and lower limits, whether high or low score is good outcome).
Results: number of participants allocated to each intervention group, missing participants, means, standard deviations, proportions, estimate of effect with confidence interval, P value, subgroup analysis information when appropriate (e.g. monitors and blunters (information seekers or avoiders), see Miller 1983).
Study withdrawals or losses to follow‐up.

We described interventions according to whether they contained procedural information, sensory information, behavioural instruction, cognitive intervention, relaxation techniques, hypnosis or emotion‐focused interventions. We coded preparation received by control group participants in the same way.

We (RP) contacted study authors for additional data. We used a two‐stage approach. A first email asked for key information: whether (if not stated) general anaesthesia was used, whether they measured any outcomes not reported in the paper and whether they knew of other (e.g. unpublished) studies. We also asked the study authors if they would be happy for us to contact them with additional questions. If the study authors replied and were happy for us to ask them for further information, we sent them a more detailed email if further information was required.

Assessment of risk of bias in included studies

Two review authors (RP and either MU, AM, JB, CV, MJ, JB, NS or research assistant Louise Pike) independently assessed studies' risk of bias using the tool described in Chapter 8 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). This tool requires the review authors to assess risk of bias in the following domains: sequence generation, allocation concealment, blinding of participants, personnel and outcome assessors, incomplete outcome data, selective outcome reporting and other sources of bias. In addition, the review authors noted whether the study used intention‐to‐treat analysis methods (Hollis 1999) (see Appendix 7 for table). We used a single criterion to classify studies as following the intention‐to‐treat principle: participants needed to be kept in the intervention groups to which they were randomized, regardless of the intervention they received (i.e. analysis was not according to per‐protocol or treatment‐received).

Studies with high or unclear risk of bias were to be given reduced weight in the meta‐analysis compared with studies at low risk of bias. We anticipated that meta‐analysis would be restricted to studies at low (or lower) risk of bias, as per Section 8.8.3.1 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). We planned to conduct sensitivity analyses to determine whether excluding studies at a high risk of bias affected the results but we did not do so because of the low number of studies deemed to be at `low risk' of bias (see Risk of bias in included studies). We did not expect blinding of participants or personnel administering the intervention because of the interactive nature of the interventions. We described any blinding that was carried out, and rated the risk of bias following the Cochrane guidelines, but high risk of bias for performance bias was not seen to diminish the quality of the paper. We recorded the adequacy of the blinding of outcome assessors (returning data by post was deemed acceptable).

Measures of treatment effect

We performed meta‐analyses according to the recommendations of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). For dichotomous variables, we planned to calculate risk ratios (RR) with 95% confidence intervals (CI). For continuous data where each study used the same units (i.e. for length of stay), we calculated mean differences for each study and their 95% CIs.

For the postoperative pain and negative affect outcomes a variety of scales were used so we calculated a standardized effect size ‐ the standardized mean difference (SMD), or Hedges' g. We used final scores as standard. However, some studies only reported mean (SD) change from baseline; for these studies we used the difference in mean change scores as the effect size. If no continuous postoperative pain data were available but dichotomous data were presented, we used the log odds ratio instead as the effect size. It was only necessary to do this for one study (Coslow 1998).

If necessary, we reversed the sign of the effect size so that values below zero always indicated that the intervention group was favoured.

Unit of analysis issues

We included only patient‐randomized studies in the meta‐analyses. We reported the results of cluster‐randomized studies as part of the narrative review.

Dealing with missing data

If any necessary data were missing, when we contacted authors about their studies we specifically asked them about the missing data (see Data extraction and management for procedure taken with contacting authors). Missing standard deviations (SD) was a common situation in this review. We were able to calculate (or estimate) standard deviations in a variety of ways. These included calculating the SD from the standard error of the mean (SEM), 95% confidence intervals or from t or F statistics. If the majority of studies in a meta‐analysis still had missing SDs we did not impute these. Otherwise, we used an unweighted average of SDs from other studies in the review. We used identical imputed values for both intervention and control groups.

Assessment of heterogeneity

We considered and tested heterogeneity between trials, where appropriate. To test for gross statistical heterogeneity between all trials, we used Chi² tests for heterogeneity and quantified heterogeneity using the I² statistic (Higgins 2011).

Assessment of reporting biases

We did not plan to assess reporting biases using, for example, funnel plots, because of the probable heterogenous nature of the studies and probable small number of studies appropriate for comparison. However, there proved sufficient studies to examine funnel plots for the overall, `omnibus' analyses.

Data synthesis

We entered quantitative data into Cochrane RevMan 5.3 software and, where appropriate, statistically aggregated the data. We pooled data for all outcomes using an inverse variance approach. We used random‐effects models for all analyses because of expected heterogeneity in interventions and outcomes.

Where it was not possible to pool data, or if summary measures were medians (with range or interquartile range (IQR)), we presented these details in table format and discussed the results.

For each outcome we performed an initial `omnibus' meta‐analysis. We use the term `omnibus' to describe an overall analysis, including all of the psychological preparation interventions (whatever the types of interventions used) and compared these (any psychological preparation intervention) versus controls.

Many studies in the review contained two or more randomized arms. We classified the interventions in each arm separately. To avoid double counting of control groups, for the omnibus analysis we pooled the data in all intervention arms using the standard pooling formula and classified the study as administering any of the interventions included in any of the pooled arms.

The only non‐standard design (i.e. non individually randomized controlled trial) that met the inclusion criteria was a clustered randomized controlled trial design. We narratively synthesized these studies ‐ they were not included in meta‐analysis.

`Summary of findings' table

We included each outcome (postoperative pain, behavioural recovery, negative affect and length of stay) in a `Summary of findings' table (Table 1). For each outcome, the table indicated the effect for the control group and corresponding effect for the intervention group as appropriate, with the number of studies and participants included in analyses. We assessed the quality of the body of evidence for each outcome (postoperative pain, behavioural recovery, negative affect, length of stay) using the GRADE approach, as described in Chapter 12 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). As we only included RCTs, our start point for grading the evidence was `high quality'. We downgraded by one level for serious factors, and two levels for very serious factors in: limitations in design or implementation of studies (risk of bias); indirectness of evidence; heterogeneity or inconsistency of results; imprecision of results; or high likelihood of publication bias.

Summary of findings for the main comparison. Any intervention compared to control for adults undergoing surgery under general anaesthesia.

Any psychological preparation intervention compared to control for adults undergoing surgery under general anaesthesia
Patient or population: adults undergoing elective surgery under general anaesthesia Setting: pre‐surgical contexts (typically hospitals/preoperative clinic settings); setting was not limited by country/language/type of hospital  Intervention: psychological preparation interventions presented to participants preoperatively; interventions contained one or more of the following components: procedural information; sensory information; behavioural instruction; cognitive intervention; relaxation techniques; hypnosis; emotion‐focused intervention  Comparison: control group (typically standard care and/or attention control)
Outcomes	*Illustrative comparative risks (95% CI)**		Relative effect  (95% CI)	No of participants  (studies)	Quality of the evidence  (GRADE)	Comments
	Assumed risk	Corresponding risk
	Control	Any intervention
Postoperative pain ‐ measured with a range of tools and placed on a standardized scale Higher scores = higher pain	‐	The mean pain in the intervention group was 0.2 (95% confidence interval 0.35 to 0.06) standard deviations lower	‐	2713  (38 RCTs)	⊕⊕⊝⊝  LOW¹	‐
Behavioural recovery ‐ measured with a range of tools	Insufficient data were available to calculate standardized scores	Findings suggested that psychological preparation has potential to improve behavioural recovery outcomes, but no clear conclusions could be reached	‐	1441 participants were randomized (14 RCTs)	⊕⊝⊝⊝  VERY LOW²	Data from studies were not combined in meta‐analysis because of a low number of studies containing suitable data and a wide range of outcome measures
Length of stay in hospital (days)	The mean length of stay for the control groups ranged from 2.11 to 18.6 days	The mean length of stay (days) in the intervention group was 0.52 days fewer (95% confidence interval 0.82 to 0.22)	‐	3313  (36 RCTs)	⊕⊕⊝⊝  LOW³	‐
Negative affect ‐ measured with a range of tools and placed on a standardized scale Higher scores = higher negative affect (e.g. more anxiety)	‐	The mean negative affect in the intervention group was 0.35 (95% confidence interval 0.54 to 0.16) standard deviations lower	‐	2496  (31 RCTs)	⊕⊕⊝⊝  LOW⁴	‐
The basis for the assumed risk* (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).  CI: confidence interval; RCT: randomized controlled trial
GRADE Working Group grades of evidence  High quality: Further research is very unlikely to change our confidence in the estimate of effect.  Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.  Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.  Very low quality: We are very uncertain about the estimate.

Author, year	Surgery type and sample size (randomized)	Intervention categories	Pain measure(s) The first measure listed is that prioritized in this review	Pain findings (as available)
Chumbley 2004	Mixed: surgeries that would receive PCA routinely N = 246	Intervention 1: Behavioural instruction (delivered in leaflet) Intervention 2: Behavioural instruction (delivered in interview)	1) Visual analogue scale (VAS) days 1 to 5 post‐surgery 2) Word rating on 5‐point scale; days 1 to 5 post‐surgery	Cluster‐randomized VAS day 1 postoperatively mean (95% CI): Control: 3.7 (2.93 to 4.45); Intervention 1: 2.8 (2.04 to 3.56); Intervention 2: 3.2 (2.43 to 6.21). ANOVA, repeated measures: for VAS pain scores, between‐groups effect: F = 1.88, P value = 0.23
Daltroy 1998	Total hip or knee arthroplasty N = 12	Procedural and sensory information	Day 4 post‐surgery Measure not clearly described, assume same as preoperatively: mean of 3 x 5‐point scales assessing pain at night, resting and when active	Intervention did not affect pain in general linear model (P value = 0.16)
Dewar 2003	Mixed surgeries N = 254	Procedural information, behavioural instruction, cognitive intervention, relaxation	Evening after surgery (day 0) Brief Pain Inventory: numerical rating scale from 0 to 10	Control n = 118; intervention n = 104 No significant difference
Enqvist 1997	Breast reduction N = 50	Relaxation, hypnosis	Days 1 to 5 post‐surgery, measured with `10‐degree VAS’. Not clear exactly what was asked, or if measured once in this period or daily	Control n = 25; intervention n = 23 No significant differences
Ferrara 2008	Total hip replacement N = 23	Behavioural instruction	15 days and 4 weeks post‐surgery: VAS Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) subscale	Control n = 12; intervention n = 11 VAS pain scores: significantly lower in intervention group at 4 weeks (not at 15 days apparently)
Field 1974	Mixed orthopaedic surgery N = 60	Procedural information, hypnosis	Between 2 and 7 days post‐surgery; no further information	Control n = 30; intervention n = 30 No significant difference
Gilbey 2003	Total hip arthroplasty N = 76	Behavioural instruction	3 weeks post‐surgery Pain domain of WOMAC	Control n = 25; intervention n = 32 Significant difference (P value < 0.01) for total WOMAC (pain, physical function and stiffness) and physical function domain. Reports surgery had such beneficial effect on pain that impact of intervention only marginal.
Hawkins 1993	Gynaecological surgery N = 60	Behavioural instruction	48 hours post‐surgery: VAS of average pain; categorical scale (5 categories from no pain to unbearable pain); nurse ratings of pain (collected hourly pain reports when not sleeping for first 48 hours after surgery)	Control n = 40 (standard care and attention control); intervention n = 20 No significant differences (VAS ANOVA F = 0.06, df = 2, P value = 0.93)
Johnson 1978b	Sample 1: cholecystectomy, N = 81 Sample 2: inguinal hernia repair, N = 68	Intervention 1: ‘Instruction’: Behavioural instruction (deep breathing, coughing, leg exercises) Intervention 2: ‘Procedure information’: focus procedural information, also some sensory information and behavioural instruction Intervention 3: `Sensation information’: focus: sensory information, also some procedural information and behavioural instruction 2 x 3 factorial design: no instruction/instruction (Intervention 1; no information/information (Interventions 2 and 3)	Pain: days 1, 2 and 3 post‐surgery: intensity of sensations on 10‐point scale Scores totaled over the 3 days in analysis	Sample 1 No main effect of condition Sample 2 MANOVA with DVs pain and distress of pain sensation: for first postoperative day: significant main effects for information level (F(4, 104) = 2.55, P value < 0.05), trend for an effect for instruction (F(2, 52) = 3.07, P value = 0.055), but only a main effect for distress scores reported (no univariate findings reported for pain – so seems no significant effects)
Johnson 1985	Abdominal hysterectomy N = 199	Intervention 1: Procedural and sensory information Intervention 2: ‘Cognitive‐coping technique’ – cognitive intervention Intervention 3: ‘Behavioural‐coping technique’ – behavioural instruction 2x3 factorial design: no information/information (Intervention 1); no coping technique/coping technique (Interventions 2 and 3)	Day 3 post‐surgery Pain scale from 1 to 10	MANOVA, controlling for covariates, with various outcomes including pain: ‘significant’ at P value < 0.10: coping technique, F (16, 286) = 1.59, P value =0.07. However, pain does not appear to be one of the outcomes responsible for this.
Kulkarni 2010	Major abdominal surgery N = 80	Intervention 1: Behavioural instruction (deep breathing training) Intervention 2: Behavioural instruction (incentive spirometry) Intervention 3: Behavioural instruction (specific inspiratory muscle training)	Pain (no information of how measured/when)	Control n = 17; intervention 1 n = 17; intervention 2 n = 15; intervention 3 n = 17. Median pain score for all groups is 3 (no ranges/IQRs)
Lilja 1998	Breast cancer (BC) surgery N = 46 Total hip replacement (THR) N = 55	Procedural information, behavioural instruction	First 3 days post‐surgery: VAS	Control: n = 22, mode = 1 (BC day 1); intervention n = 22 No significant differences groups for either BC or THR patients (analysed separately)
Liu 2004	Mixed orthopaedic surgery N = 74	Cognitive intervention	Pain: 0 to 10 VAS; timing not stated	Control n = 35, mean (SD)= 2.5 (0.52); intervention n = 39, mean = 2.85 (0.33) Significant difference (t = 2.61, P value < 0.05). Discussion: authors state “patients from the experimental group…had…low scores on pain compared to the control group with statistical significance” (p5). This appears to be at odds with mean scores, suggesting error in paper.
Oetker‐Black 2003	Total abdominal hysterectomy N = 108	Behavioural instruction, cognitive intervention, relaxation	Day 1 post‐surgery: VAS At discharge: bodily pain (Health Status Questionnaire)	No significant differences (VAS: t(1,105) = ‐0.54, P value = 0.591)
Parthum 2006	Cardiac surgery N = 93	Procedural information, sensory information, behavioural instruction	1. Pain intensity: VAS as part of modified McGill Pain Questionnaire (MPQ), day 1 postoperative and retrospective rating of pain while on ICU 2. Proportion of patients in pain postoperatively (cut off: VAS > 3 on above measures)	Cluster‐randomized Control n = 36, median (VAS current, at rest) = 4.0. Intervention: n = 37, median = 3.0 No significant differences between groups
Perri 1979	Vaginal hysterectomy N = 26	Relaxation	Self report. 1 and 3 days postoperation; ‘McGill‐Melzack Pain Questionnaire’ Observed. 1 and 3 days postoperation – observed pain behaviour – Chambers‐Price Rating Scale for Pain	Control n = 13; intervention mean = 13. No significant differences between groups (P value < 0.05)
Shelley 2007	Coronary artery bypass surgery N = 90	Cognitive intervention	At discharge (4 days post‐surgery): 10 cm VAS	Control n = 43; intervention n = 37 Significant interaction between group, self efficacy and external health locus of control (F(1,71) = 4.06, P value < 0.05). Post hoc analysis: trend‐level effects: smaller increase in pain for prepared patients than controls if high external health locus of control and low self efficacy. Matched control appraisal patients: increased pain in intervention group compared with controls (controlling for baseline pain).
Shuldham 2002	Coronary artery bypass surgery N = 356	Procedural information, behavioural instruction	Questionnaires presented on day 3 post‐surgery (or 3rd day after transfer to ward if still in intensive care unit on day 3 post‐surgery) Composite measure (including VAS, body map and categorical rating scale), authors used VAS in analysis	No significant differences (using Mann‐Whitney U): U = 10,197.5; Z = ‐0.72, P value = 0.47
Vukomanović 2008	Total hip arthroplasty N = 45	Procedural information, behavioural instruction	VAS at discharge: pain at rest and movement	Cluster‐randomized Control n = 20, mean (SD) = 6.2 (14.95); Intervention n = 20, mean (SD) = 3.95 (13.08) No significant difference in pain
Watt‐Watson 2004	Coronary artery bypass surgery N = 406	Behavioural instruction, cognitive intervention	Days 1 to 5 post‐surgery: McGill Short‐form. Scores: Present Pain Intensity: most severe pain in previous 24 hours Pain Rating Index (sensory, affective and total); Numerical Rating Scale (on moving and worst pain in previous 24 hours)	No main effect of group
Wells 1982	Cholecystectomy N = 12	No control group Intervention 1: ‘Control’: Sensory information; behavioural instruction Intervention 2: (do not appear to receive ‘control’ intervention) Relaxation	Rated on 10 cm line on evening on day of surgery, and days 1 and 2 post‐surgery	Intervention 1: n = 6, mean (SD) eve of operation = 5.4 (3.39); intervention 2: n = 6, mean (SD) = 5.65 (1.6) No main effect for treatment (F(1,7) = 3.0, P value = 0.13), time (F(7,2) = 3.3, P value = 0.07) or interaction between treatment and time (F(2,4) = 1.0, P value = 0.4)
Wijgman 1994	Total knee arthroplasty N = 64	No control group Intervention 1: Procedural information Intervention 2: Behavioural instruction	2, 5, 7, 10, 14 days post‐surgery and at discharge. VAS where 100 = worst pain	Overall n at day 2 = 63. Medians (IQRs) presented in Figure 1, not clear. No significant differences between groups
Ziemer 1982	Gynaecologic or gastrointestinal N = 111	Intervention 1: Sensory information Intervention 2: Sensory information, behavioural instruction, cognitive intervention, relaxation	2 to 4 days post‐surgery: 5‐point pain intensity rating scale	Control n = 40; intervention 1 n = 34; intervention 2 n = 37 Focus: correlation of pain with coping scales

Continuous data
Outcome (add label)	Intervention 1 (state)		Control
	N	Mean (SD)	N	Mean (SD)
1.
2.
3.
Outcome (add label)	Intervention 2 (state)		Control
	N	Mean (SD)	N	Mean (SD)
1.
2.
3.
Outcome (add label)	Intervention 3 (state)		Control
	N	Mean (SD)	N	Mean (SD)
1.
2.
3.

Dichotomous data
Outcome (add label)	Intervention 1 (n/N) n = no. participants with the outcome N = no. participants at risk of outcome	Control (n/N) n = no. participants with the outcome N = no. participants at risk of outcome
1.
2.
3.
Outcome (add label)	Intervention 2 (n/N) n = no. participants with the outcome N = no. participants at risk of outcome	Control (n/N) n = no. participants with the outcome N = no. participants at risk of outcome
1.
2.
3.
Outcome (add label)	Intervention 3 (n/N) n = no. participants with the outcome N = no. participants at risk of outcome	Control (n/N) n = no. participants with the outcome N = no. participants at risk of outcome
1.
2.
3.

Domain	Support for judgement	Review authors’ judgement
Selection bias		High risk, low risk or unclear
Random sequence generation	Describe the method used to generate the allocation sequence in sufficient detail to allow an assessment of whether it should produce comparable groups.	Selection bias (biased allocation to interventions) due to inadequate generation of a randomized sequence.
Allocation concealment	Describe the method used to conceal the allocation sequence in sufficient detail to determine whether intervention allocations could have been foreseen in advance of, or during, enrolment.	Selection bias (biased allocation to interventions) due to inadequate concealment of allocations prior to assignment.
Performance bias
Blinding of participants and personnel	Describe all measures used, if any, to blind study participants and personnel from knowledge of which intervention a participant received. Provide any information relating to whether the intended blinding was effective.	Performance bias due to knowledge of the allocated interventions by participants and personnel during the study.
Detection bias
Blinding of outcome assessment (please note if this differs with different outcomes)	Describe all measures used, if any, to blind outcome assessors from knowledge of which intervention a participant received. Provide any information relating to whether the intended blinding was effective.	Detection bias due to knowledge of the allocated interventions by outcome assessors.
Attrition bias
Incomplete outcome data Outcome: (add a table line for each additional outcome, if differs)	Describe the completeness of outcome data for each main outcome, including attrition and exclusions from the analysis. State whether attrition and exclusions were reported, the numbers in each intervention group (compared with total randomized participants), reasons for attrition/exclusions where reported, and any re‐inclusions in analyses performed by the review authors.	Attrition bias due to amount, nature or handling of incomplete outcome data
Reporting bias
Selective reporting	State how the possibility of selective outcome reporting was examined by the review authors, and what was found.	Reporting bias due to selective outcome reporting.
Other bias
‘Intention‐to‐treat’ SeeHiggins 201116.2.1.	Were participants kept in the intervention groups to which they were randomized, regardless of the intervention they received? Alternative possibilities: per‐protocol (only analysed if received some of allocated treatment) or treatment‐received (allocated according to the treatment received rather than that to which randomized).	Bias due to analysis being per‐protocol or treatment‐received.
Other sources of bias e.g. contamination, clustering?	State any important concerns about bias not addressed in the other domains in the tool.	Bias due to problems not covered elsewhere in the table.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain	38	2713	Std. Mean Difference (Random, 95% CI)	‐0.20 [‐0.35, ‐0.06]
2 Length of stay (days)	36	3313	Mean Difference (IV, Random, 95% CI)	‐0.52 [‐0.82, ‐0.22]
3 Negative affect	31	2496	Std. Mean Difference (Random, 95% CI)	‐0.35 [‐0.54, ‐0.16]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain	12	1051	Std. Mean Difference (Random, 95% CI)	‐0.08 [‐0.26, 0.09]
1.1 Procedural information only	2	186	Std. Mean Difference (Random, 95% CI)	‐0.13 [‐0.42, 0.16]
1.2 Procedural information plus other intervention(s)	10	865	Std. Mean Difference (Random, 95% CI)	‐0.08 [‐0.29, 0.13]
2 Length of stay (days)	19	1983	Mean Difference (IV, Random, 95% CI)	‐0.63 [‐1.08, ‐0.18]
2.1 Procedural information only	1	76	Mean Difference (IV, Random, 95% CI)	‐6.0 [‐9.95, ‐2.05]
2.2 Procedural information plus other intervention(s)	18	1907	Mean Difference (IV, Random, 95% CI)	‐0.57 [‐1.01, ‐0.13]
3 Negative affect	17	1334	Std. Mean Difference (Random, 95% CI)	‐0.45 [‐0.75, ‐0.16]
3.1 Procedural information only	3	269	Std. Mean Difference (Random, 95% CI)	‐0.54 [‐1.25, 0.16]
3.2 Procedural information plus other intervention(s)	14	1065	Std. Mean Difference (Random, 95% CI)	‐0.43 [‐0.77, ‐0.10]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain	11	881	Std. Mean Difference (Random, 95% CI)	‐0.22 [‐0.47, 0.02]
1.1 Sensory information plus other intervention(s)	11	881	Std. Mean Difference (Random, 95% CI)	‐0.22 [‐0.47, 0.02]
2 Length of stay (days)	14	1236	Mean Difference (IV, Random, 95% CI)	‐0.71 [‐1.15, ‐0.27]
2.1 Sensory information plus other intervention(s)	14	1236	Mean Difference (IV, Random, 95% CI)	‐0.71 [‐1.15, ‐0.27]
3 Negative affect	12	919	Std. Mean Difference (Random, 95% CI)	‐0.55 [‐0.90, ‐0.19]
3.1 Sensory information plus other intervention(s)	12	919	Std. Mean Difference (Random, 95% CI)	‐0.55 [‐0.90, ‐0.19]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain	21	1241	Std. Mean Difference (Random, 95% CI)	‐0.14 [‐0.33, 0.05]
1.1 Behavioural instruction only	9	523	Std. Mean Difference (Random, 95% CI)	0.01 [‐0.19, 0.21]
1.2 Behavioural instruction plus other intervention(s)	12	718	Std. Mean Difference (Random, 95% CI)	‐0.28 [‐0.57, 0.01]
2 Length of stay (days)	25	2338	Mean Difference (IV, Random, 95% CI)	‐0.51 [‐0.84, ‐0.19]
2.1 Behavioural instruction only	8	445	Mean Difference (IV, Random, 95% CI)	‐0.26 [‐0.55, 0.03]
2.2 Behavioural instruction plus other intervention(s)	17	1893	Mean Difference (IV, Random, 95% CI)	‐0.64 [‐1.12, ‐0.16]
3 Negative affect	13	1183	Std. Mean Difference (Random, 95% CI)	‐0.22 [‐0.46, 0.02]
3.1 Behavioural instruction only	3	472	Std. Mean Difference (Random, 95% CI)	0.18 [‐0.19, 0.55]
3.2 Behavioural instruction plus other intervention(s)	10	711	Std. Mean Difference (Random, 95% CI)	‐0.37 [‐0.65, ‐0.09]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain	6	355	Std. Mean Difference (Random, 95% CI)	‐0.02 [‐0.29, 0.25]
1.1 Cognitive intervention only	2	136	Std. Mean Difference (Random, 95% CI)	‐0.34 [‐0.68, ‐0.01]
1.2 Cognitive intervention plus other intervention(s)	4	219	Std. Mean Difference (Random, 95% CI)	0.17 [‐0.09, 0.44]
2 Length of stay (days)	9	1074	Mean Difference (IV, Random, 95% CI)	‐0.43 [‐1.07, 0.22]
2.1 Cognitive intervention only	2	77	Mean Difference (IV, Random, 95% CI)	0.62 [‐0.74, 1.99]
2.2 Cognitive intervention plus other intervention(s)	7	997	Mean Difference (IV, Random, 95% CI)	‐0.59 [‐1.27, 0.08]
3 Negative affect	5	251	Std. Mean Difference (Random, 95% CI)	‐0.20 [‐0.52, 0.12]
3.1 Cognitive intervention only	3	173	Std. Mean Difference (Random, 95% CI)	‐0.08 [‐0.58, 0.42]
3.2 Cognitive intervention plus other intervention(s)	2	78	Std. Mean Difference (Random, 95% CI)	‐0.39 [‐0.83, 0.05]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain	13	891	Std. Mean Difference (Random, 95% CI)	‐0.46 [‐0.81, ‐0.11]
1.1 Relaxation only	7	417	Std. Mean Difference (Random, 95% CI)	‐0.71 [‐1.29, ‐0.13]
1.2 Relaxation plus other intervention(s)	6	474	Std. Mean Difference (Random, 95% CI)	‐0.19 [‐0.58, 0.21]
2 Length of stay (days)	7	473	Mean Difference (IV, Random, 95% CI)	‐0.97 [‐1.94, ‐0.00]
2.1 Relaxation only	2	60	Mean Difference (IV, Random, 95% CI)	‐0.80 [‐2.25, 0.64]
2.2 Relaxation plus other intervention(s)	5	413	Mean Difference (IV, Random, 95% CI)	‐1.08 [‐2.39, 0.24]
3 Negative affect	11	687	Std. Mean Difference (Random, 95% CI)	‐0.34 [‐0.56, ‐0.12]
3.1 Relaxation only	4	256	Std. Mean Difference (Random, 95% CI)	‐0.26 [‐0.57, 0.04]
3.2 Relaxation plus other intervention(s)	7	431	Std. Mean Difference (Random, 95% CI)	‐0.40 [‐0.73, ‐0.08]

Methods	Randomized controlled trial
Participants	30 patients undergoing planned urinary diversion surgery for bladder cancer. Control group: mean age 45.86 (SD = 4.4); intervention mean age: 45.33 years (SD = 5.9) (overall mean = 45.60). Control group: 12 male, 3 female; intervention group 11 male, 4 female. Overall, 76.7% male. Setting: The National Cancer Institute, Cairo, Egypt. Dates of data collection not provided.
Interventions	Control: "routine physical pre‐operative care" Intervention: explanation of surgical procedure, appearance of stoma and postoperative device, reasons for wearing device, visit from a previous patient; encouraged to "express fears and anxieties regarding social aspects of living with a stoma". Emotion‐focused; procedural information
Outcomes	Negative affect: anxiety (STAI A‐state, Arabic translation) on 3^rd postoperative day and before discharge (approximately 12 days post‐surgery)
Notes	Attempted to contact authors; no reply received
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	p238: "After patients consented, they were assigned randomly to two groups of 15 each (control and experimental)"
Allocation concealment (selection bias)	Unclear risk	No further information provided
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Not stated but unlikely participants blinded due to nature of intervention
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	No information provided in paper
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	No information – numbers only reported for 30 people with complete data
Selective reporting (reporting bias)	Unclear risk	Consistent throughout paper but no reference to a protocol document to check this
‘Intention‐to‐treat’	Unclear risk	No information provided related to `intention‐to‐treat'
Other bias	Low risk	No obvious other biases

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Negative affect	2	72	Std. Mean Difference (Random, 95% CI)	‐0.77 [‐1.25, ‐0.30]
1.1 Hypnosis plus other intervention(s)	2	72	Std. Mean Difference (Random, 95% CI)	‐0.77 [‐1.25, ‐0.30]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain	3	180	Std. Mean Difference (Random, 95% CI)	‐0.42 [‐0.85, 0.00]
1.1 Emotion‐focused only	1	18	Std. Mean Difference (Random, 95% CI)	0.12 [‐0.76, 1.00]
1.2 Emotion‐focused plus other intervention(s)	2	162	Std. Mean Difference (Random, 95% CI)	‐0.54 [‐0.97, ‐0.10]
2 Length of stay (days)	3	212	Mean Difference (IV, Random, 95% CI)	0.14 [‐0.67, 0.94]
2.1 Emotion‐focused plus other intervention(s)	3	212	Mean Difference (IV, Random, 95% CI)	0.14 [‐0.67, 0.94]
3 Negative affect	4	201	Std. Mean Difference (Random, 95% CI)	‐0.24 [‐0.55, 0.07]
3.1 Emotion‐focused only	1	18	Std. Mean Difference (Random, 95% CI)	0.12 [‐0.76, 1.00]
3.2 Emotion‐focused plus other intervention(s)	3	183	Std. Mean Difference (Random, 95% CI)	‐0.30 [‐0.66, 0.06]

Methods	Cluster‐randomized controlled trial
Participants	UK‐based study, funded by London Regional NHS Executive, Research and Development Directorate; dates not provided. 246 undergoing surgery where would routinely receive patient‐controlled analgesia (PCA). Gynaecological 87; orthopaedic 77; abdominal 23; urology/renal 19; thoracic: 13; breast: 4; pancreatic/biliary 1; plastic 1. Control mean age 54 (range 19 to 80); Intervention 1: 59 (21 to 83); Intervention 2: 58 (17 to 78). Control: 48 female, 27 male; Intervention 1: 44 female, 31 male; Intervention 2: 45 female; 30 male. Overall: 137 female, 88 male, 60.89% female
Interventions	Control: "routine information" – brief visit from anaesthetist; information on PCA would be limited. Author: anaesthetist had approximately 30 minutes to see 5 to 6 patients so brief; information not controlled. Intervention 1: Leaflet presented night before surgery. Included behavioural instruction – e.g. drug = morphine, could not overdose/become addicted; side effects; directions to seek help with side effects and how to use PCA; how long it took to work, why bleeped and why lock‐out period. Intervention 2: Interview: content as per leaflet; delivered night before surgery in 20‐minute interview; PCA pump taken to interview (behavioural instruction)
Outcomes	Negative affect: anxiety (Hospital Anxiety and Depression Scale) 24 to 72 hours post‐surgery Negative affect: tension/anxiety (Profile of Mood States) 24 to 72 hours post‐surgery Pain: VAS days 1 to 5 post‐surgery Pain: word rating; days 1 to 5 post‐surgery
Notes	Author provided information regarding risk of bias and study methods
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	p355: "Cluster randomisation was used because patients using PCA were often allocated to adjacent beds in the surgical wards…Fifteen patients were allocated to each cluster. Once recruited, there was a ‘clear out’ period to allow patients to be discharged. Recruitment to the next cluster then began. As the type of surgery could influence many of the outcome variables, the randomisation was stratified so that the intervention groups contained patients having similar operations". Author: "Clinstat [a computer program] was used to generate the allocations".
Allocation concealment (selection bias)	Unclear risk	No information in paper. Author responded but still unclear. As cluster‐randomized the issues in this paper are different to those using individual‐level randomization
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Patients appear to have been blinded to the fact that there was a study and that they would be receiving different information – both because of randomization methods to avoid contamination, and by what they were told – "asked to take part in ‘a survey of their opinions of their postoperative pain relief" (p355). However, the person giving the leaflet – and, in particular, giving the interview – would have known which condition they were in
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	p355: "The other researchers were blinded to the intervention that patients received". This suggested that the researcher presenting the questionnaire could be blind, but it does not state that the person giving the intervention was not the same person collecting outcomes
Incomplete outcome data (attrition bias)   All outcomes	Low risk	Attrition reported: 21 excluded for reasons to do with the hospital treatment provided (p355: 10 returned to ward without PCA; 7 admitted to intensive therapy unit; 2 had operations cancelled; 2 returned to ward with pethidine PCA) and 5 were too unwell to complete postoperative anxiety measures (p355). Unfortunately authors do not say how many lost from each group so unclear whether any likely bias. Additional information from authors: for those too unwell to complete HADS, 2 from control group, 3 interview group and 0 in written group. 2 patients failed to complete both pain measures on day 1; 6 on day 2; author uncertain which groups they were from. Given the size of the study (n = 246) we believe attrition at this level is unlikely to have significant impact
Selective reporting (reporting bias)	Unclear risk	Some mis‐match between measures reported in Methods and those in Results – e.g. pain word results not presented, only HADS and POMS anxiety measures. However, most reported results ns so this might be more down to word count than selective outcome reporting. No protocol referred to. Authors responded to contact: "All outcomes were published", but kept as `unclear' after discussion between extractors
‘Intention‐to‐treat’	Unclear risk	No information in paper. Author: "No the data were not analysed on an intention to treat basis. A few patients dropped out after recruitment, some went to ICU unscheduled, some declined PCA, some had the operation cancelled. The patient had to return to the ward on morphine PCA to be included in the analysis." Author uses vigorous standard of intention‐to‐treat rather than our criterion on whether kept in intervention group to which randomized ‐ the issues raised here are covered by our assessment of attrition bias
Other bias	Low risk	No other concerns

Methods	Randomized controlled trial (pilot/feasibility study)
Participants	26 patients undergoing coronary artery bypass surgery, October to December 2002 (only those at high risk of developing a postoperative pulmonary complication). Research team located in Utrecht, Netherlands. 13 male, 13 female. Intervention group (n = 14), mean age 70.1 (SD 9.9), control group (n = 12) mean age 70.5 (10.1)
Interventions	Control: usual care: included "education about early mobilization, and coughing with wound support", 1 day preoperative. Behavioural instruction Intervention: as Control, plus: inspiratory muscle training for 2 to 4 weeks pre‐operation Daily training at home, 20‐minute sessions, 1/week supervised by a physical therapist. Instructed to keep a daily diary and trained to use inspiratory threshold‐loading device. Behavioural instruction (beyond that received by control group)
Outcomes	Length of stay
Notes	Information from author used in assessing risk of bias
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	p953: "randomly assigned using a computer‐generated randomised block design (block of four people)"
Allocation concealment (selection bias)	Unclear risk	No information provided in paper
Blinding of participants and personnel (performance bias)   All outcomes	High risk	As involved significant preoperative training, provided by a physical therapist, neither participants nor therapist would have been blind
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	"All measurements were taken by an experienced physical therapist (EH) who was blinded for the group allocation of the patients"
Incomplete outcome data (attrition bias)   All outcomes	Low risk	Flow chart p952: 0 participants excluded from analysis
Selective reporting (reporting bias)	Low risk	Means and SDs provided for the outcome relevant to review. No evidence of selective reporting, and authors responded to our queries stating that every outcome measured was reported
‘Intention‐to‐treat’	Low risk	Flow chart p952: in each group, all received allocated intervention
Other bias	Low risk	No other concerns

Methods	Randomized controlled trial (2 x 2 design)
Participants	50 patients undergoing cholecystectomy at a 500‐bed hospital, St Joseph Mercy Hospital, Ann Arbor, Michigan, USA (dates not provided). Mean age: 43.6 years (range: 20 to 72). 38 (76%) female; 12 male
Interventions	Control: no treatment control Intervention 1: pamphlet containing procedural information: information about operative events; also behavioural instruction e.g. instructions in deep breathing, leg exercises Intervention 2: nurse visit providing same content as 1; also assisted patient in practising exercises until mastery achieved Intervention 3: both pamphlet and nurse visit
Outcomes	Length of stay: number of days between surgery and discharge Negative affect: day 2 post‐surgery. Mood Adjective Checklist: 15 adjectives describing the 5 mood dimensions: well‐being, happiness, fear, helplessness, anger
Notes	Data only presented grouped by preoperative fear level, adjusted for age Behavioural recovery and negative affect were measured, but using scales without published psychometric information Author provided some information regarding risk of bias (stage 1 response only)
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	p7: "Patients were randomly assigned to one of four experimental groups"
Allocation concealment (selection bias)	Unclear risk	No information provided in paper
Blinding of participants and personnel (performance bias)   All outcomes	High risk	p7: "surgeons and the nursing staff were uninformed as to the specific dependent variables being studied and the assignment of patients to the experimental groups". But the participants would have known and all interventions were provided by the same nurses
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	p8: "Patients…were visited both pre‐and postoperatively by the same nurse who visited the patients in the other conditions. The purpose of the visits was to explain the study, secure patient consent and collect data. The data collection and preoperative interventions were carried out by the same two nurses over a period of 2 ½ months." However, as the outcome of interest to us is length of stay it is not clear how lack of blinding could influence outcome assessment. Therefore rating of `unclear' rather than `high' risk
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	Attrition and exclusions were reported (p7): 1 had an atypical cholecystectomy; for 5 patients the nurse‐experimenter was unable to collect all observations; 1 patient in the pamphlet‐only group did not read the pamphlet. The authors do not report how many participants were lost from each group, so the impact in terms of bias is unknown. However, the participant who was excluded for not reading the pamphlet is unlikely to have been excluded if they were in a different group
Selective reporting (reporting bias)	High risk	The analyses did not allow the authors’ primary aims to be addressed. The stated purposes were (p7): "1) to test the effects of providing instruction about the usual events of surgery and instructions in leg exercises, turning in bed, getting out of bed, and coughing and deep breathing; and 2) to compare the relative impact of two information‐delivery methods on various indicators of postoperative recovery, using as delivery methods a preoperative nurse visit and/or pamphlet". However, data addressing these aims are not provided; all data are split according to low or high preoperative fear. This splitting was not only not pre‐specified, but seems likely to have resulted in unreliably small sample sizes. Data appropriate for meta‐analysis are not provided for either length of stay or negative affect outcome
‘Intention‐to‐treat’	High risk	Not intention‐to‐treat: p7: the patient who reported not having read the pamphlet in the pamphlet‐only condition was excluded from analysis
Other bias	Unclear risk	Potential for contamination across groups (e.g. pamphlets could be passed around)

Methods	Randomized controlled trial ‐ analysed as 2 x 2 factorial design
Participants	60 adults undergoing mixed surgery ‐ including hysterectomy, hernia repair, cholecystectomy, transurethral resection, tubal ligation, D and C ‐ at Yale ‐ New Haven Hospital, USA (dates not provided). No information on age or gender
Interventions	Control: attention control; administered as all conditions: 20‐minute interview a short time after admission Intervention 1: "Coping device" – trained in cognitive reframing – focusing on positive aspects of a situation. Cognitive intervention Intervention 2: "Preparatory information" – discussed practices e.g. skin preparation, anaesthesia and what could expect after surgery, e.g. nausea, pain; reassured re. high quality of staff. Procedural and sensory information Intervention 3: "Combination" – combined components of Intervention 1 and Intervention 2, in briefer format so still approximately 20 minutes long. Cognitive intervention, procedural and sensory information
Outcomes	Length of stay
Notes	Author provided details regarding risk of bias
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	p158: "Subjects were assigned to conditions on a stratified random basis, so that the experimental groups were equated on five relevant background factors: type of operation, seriousness of operation, sex, age, and religious affiliation"
Allocation concealment (selection bias)	Unclear risk	No information provided in paper
Blinding of participants and personnel (performance bias)   All outcomes	High risk	It is possible that participants were blind, as all had interview of same length. However, all delivered by same investigator – investigator could not be blind p160: "All physicians, nurses, and others on the hospital staff were kept blind"
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	No information as to who collected length of stay data from patient record. Author confirmed outcome assessor blind to treatment
Incomplete outcome data (attrition bias)   All outcomes	Low risk	Lost 1 participant from Coping Device group (p161), so it would appear that attrition is being reported – and that the data set was almost complete
Selective reporting (reporting bias)	Low risk	All measures reportedly taken were reported in Results, but no mention of a protocol document we can refer to. Author confirmed no measures used that were not reported in Results
‘Intention‐to‐treat’	Unclear risk	It seems unlikely that patients could have changed groups, but it is not stated that intention‐to‐treat was followed
Other bias	Low risk	No other concerns

Methods	Randomized control trial
Participants	176 patients undergoing any non‐emergency surgery where expected to remain in hospital a minimum of 48 hours at the Luther Hospital, Eau Claire, Wisconsin, USA ‐ a private, non‐profit, community‐owned hospital. Included patients admitted for surgery from 6 February 1972 to 29 March 1972. 73 female, 103 (58.5%) male; aged 16+ (in group 16 to 44 years, mean = 32.03; in 35 to 59 group mean = 53.33; in 60+ group, mean age = 72.03)
Interventions	Control: visits from anaesthetist and physician/surgeon eve before surgery – described procedures; group class run by nurse – taught deep breathing, coughing, bed exercise. Procedural information; behavioural instruction Intervention: as controls, plus visit from operating room nurse shortly after admission. 2 goals: improve continuity of care and prepare patient. Visit included reviewing charts, confirming information, answering questions, if appropriate, mention might experience discomfort and should request medication if needed; give time to express feelings but not to probe deeply; determine knowledge of surgery and nursing care; explain aspects of care. As controls, plus additional procedural information and behavioural instruction and sensory information
Outcomes	Length of stay: from day before surgery; day of discharge not counted
Notes	Interested in value of preoperative visit by operating room nurse on both patient anxiety and quality of care Could not locate author
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	p8: "The investigator randomly assigned patients as their names appeared on the final typed copy of the surgery schedule to one of the two treatment groups"
Allocation concealment (selection bias)	Unclear risk	p8: "A listing of the patients to be visited was sent to the head nurse in the operating room. The head nurse then assigned nurses to make preoperative visit. A daily listing of patients included in the study was sent to the nursing units. Unit nursing personnel obtained verbal consent to participate in the study from those patients whose names appeared on the list. Patients were not told whether they would be visited". Unclear: patients would not have foreseen allocation, but does not state whether unit staff who consented participants would have known
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Both patients and staff would have known who received the intervention – the nurse visit
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	No information provided in paper
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	No attrition mentioned. Odd: states 90 randomized into intervention group, but when discussing how the group find the visit, states 96 participants – unclear – could be typo but could reflect varying sample sizes
Selective reporting (reporting bias)	Unclear risk	No evidence of measures being taken but not reported, but no reference to a protocol document
‘Intention‐to‐treat’	Unclear risk	No information provided in paper
Other bias	Low risk	No other concerns

Methods	Cluster‐randomized control trial
Participants	125 patients undergoing cholecystectomy at a 750‐bed hospital in French‐speaking community, Montreal, Canada (dates not provided). 25 male, 100 female (80% female); all were between 18 and 65 years (not clear if this is the range); mean age 41.2
Interventions	Control: no information Intervention 1: 60 to 70‐minute session, administered by nurse. Included encouragement to express feelings. Concerns, information about pre‐ and postoperative routines, demonstration of respiratory and muscular exercises, change of position and practice of exercises; description of sensation of pain and demonstration of methods to relieve it. Also "tried to help patients become aware of their capacity to influence recovery". Also given booklet containing information and instructions for exercises, including illustrations. Emotion‐focused, procedural information, sensory information, behavioural instruction. Administered at pre‐admission, 15 days before surgery Intervention 2: same as Intervention 1 but administered the afternoon before surgery
Outcomes	Negative affect: STAI (French version) State Anxiety, first 3 days after surgery Behavioural recovery: "physical functional ability", first 2 days after surgery Length of stay
Notes	Author provided some information relevant to risk of bias
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Unusual method, but reported to include an element of randomization: p228: "Patients were selected from the preadmission list of the hospital and assigned to one of three groups: For the first 2 weeks subjects were assigned to the preadmission experimental group, during the second 2 weeks to the eve‐experimental group, and during a third 2 weeks to the control group. The order of this rotating assignment was randomly chosen and was repeated 13 times". However, no details of whether patients were randomly selected from the list ‐ so potential selection bias into groups
Allocation concealment (selection bias)	High risk	No information. However, as the same order was maintained throughout study it would seem likely that it would be possible to foresee group
Blinding of participants and personnel (performance bias)   All outcomes	High risk	The nurse delivering the intervention would not be blind; if fully informed, patients also would not be blind
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	p229: "No one in the hospital knew the nature of the dependent variables. Those responsible for administering tests did not know to which group the patient belonged"
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	There is no mention of attrition (not clear if this is because of no loss, or simply not reported)
Selective reporting (reporting bias)	Low risk	Data for all outcome measures were provided (although no mention of a protocol document). However, no analysis was reported for length of stay – not clear why – most of the other findings reported are not significant so seems unlikely they would be withholding data on the basis of significance. Stage 1 email response: "There were any outcomes measured not reported in the article." We think this suggests that they have reported outcomes
‘Intention‐to‐treat’	Unclear risk	No information
Other bias	Unclear risk	Risk of contamination: Discussion (p234): "The unit staff, who took care of both groups of patients could easily have had access to the booklet given to the experimental patients and could have incorporated certain aspects of the program into their nursing approach" – aspects of this under blinding of other personnel – but also risk of contamination other than blinding influence

Methods	Randomized controlled trial: 1 control group; 3 intervention groups
Participants	268 men undergoing 1st time coronary artery bypass graft surgery (without associated procedures) at 2 hospitals in California, USA: Scripps Memorial Hospital (SMH), San Diego Veterans Affairs Medical Centre (SDVAMC) (dates not provided). Mean age: 62.52 years, SD 8.80, range 40 to 80
Interventions	Control: standard preoperative preparation, including information on how surgery is performed, length of typical stay in ICU and hospital, instructions regarding e.g. deep breathing, coughing, ambulation (procedural information, behavioural recovery) Intervention 1: "nurse tape": 15‐minute video presented evening before surgery. Nurse narration including procedures prior to surgery, anxiety, surgical procedure, intensive care phase, coming out of anaesthesia, intubation. Emphasises need for deep breathing and coughing, incentive spirometer use and ambulation. Pain, fatigue and emotional experiences discussed. Procedural and sensory information; behavioural information; emotion‐focused Intervention 2: "mastery tape": as Intervention 1, but interspersed with clips of interviews with patients as "mastery" models – "steadily improving without setbacks". 39 minutes. Procedural and sensory information; behavioural information; emotion‐focused Intervention 3: "coping tape": as Intervention 1, interspersed with clips of "coping" models – attention to setbacks, but coming through them. 39 minutes. Procedural and sensory information; behavioural information; emotion‐focused
Outcomes	Behavioural recovery: monitoring of ambulation with device that counts movements using mercury tilt switch. Worn on days 2, 3 and 4 post‐surgery at one hospital (SMH); days 3, 4, 5 post‐surgery at other hospital (SDVAMC). Worn from morning to late afternoon/early evening Length of stay: postoperative days in hospital, medical chart
Notes	Author provided information related to `Risk of bias' assessment
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	p40: "randomly assigned to view one of the three videotapes or to a control condition". Author: "In order to randomize participants to condition, one of the principal investigators (who was not involved in recruiting participants) utilized a block randomization procedure (block sizes of 20)." and "A random numbers table was used to generate the randomization sequence"
Allocation concealment (selection bias)	Low risk	No information in paper. Author: "Condition assignment was concealed from researchers in consecutively numbered, sealed envelopes. Once a participant had been enrolled and initial measures/questionnaires were completed, the researcher opened the envelope to reveal the condition letter (A, B, C, or control). The envelopes were opaque and the paper inside was folded so that there was no way for the researcher to see the condition until opening the sealed envelope"
Blinding of participants and personnel (performance bias)   All outcomes	High risk	No information in paper. Given nature of the intervention, it is possible that participant and personnel were blind – at least within the 3 videos (unlikely blind between control‐video conditions). Author: "The videotapes were marked only with a letter, researchers were not aware of which letter was associated with which condition, and the researcher did not remain in the room when participants viewed the video. Thus, researchers were blind to particular video condition (but not to whether the participant was in a video vs the control condition) throughout their contact with each participant. Participants were not aware that the study involved different conditions (at enrolment they were told simply that the study was concerned with examining some of the best methods of preparing patients for surgery, and they were told what participation would involve [e.g., completing questionnaires at 5 time points, abstraction of some information from their medical charts, etc.], but there was no mention of different conditions")
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	Outcome extracted was taken from patient notes by someone who was unaware of the allocation status of the patient “indices of preoperative physical status and speed of recovery were abstracted (unaware of condition) from participants' medical charts.” (p40)
Incomplete outcome data (attrition bias)   All outcomes	Low risk	p40: "Ten participants were eliminated from the experiment due to death or debilitating postoperative complications (e.g. stroke), leaving a final sample of 258". No information as to how the attrition distributed across groups. Author: "Four participants were lost from the Coping tape condition, 2 were lost from the Mastery Tape condition, 3 were lost from the Nurse Tape condition, and 1 was lost from the control condition (none withdrew from the study ‐ all were lost due to serious medical complications, e.g., death during surgery, debilitating stroke during the peri‐operative period)"
Selective reporting (reporting bias)	Low risk	No suggestion that measures were taken that were not reported, and analyses clearly stated prior to reporting of findings. No reference to a protocol document to check this but email from authors: "There were no major outcomes that were not reported in the paper"
‘Intention‐to‐treat’	Low risk	No information in paper. Author: "Intention to treat was used for all who were followed‐up. However, we did not impute data for those 10 patients who were entirely lost to follow‐up due to death or debilitating surgical complications" ‐ meets our criterion for intention‐to‐treat
Other bias	Low risk	No other concerns

Methods	Randomized controlled trial (a "pilot" study)
Participants	39 adults undergoing total hip arthroplasty (data for 35) ‐ at Charing Cross Hospital, London, dates not provided. Overall mean age 71.9 (SD 9.3), range 51 to 92 years. Intervention mean age 70.8 (SD 9.3), control mean age 72.8 (SD 10.1). Most (25, 71.4%) female, 10 male
Interventions	Control: standard care, included description of surgery, its risks and approximate length of stay. Procedural information Intervention: seem to have received standard care. Also: information booklet – information on surgery, pre‐ and postoperation stages, rehabilitation including exercise regimes, answers to frequently asked questions. Class 2 to 4 weeks pre‐operation – enforced booklet, checked could do exercises and understood how to use walking aids postoperation and how to make adaptations needed in homes.Procedural information (beyond controls), behavioural instruction
Outcomes	Pain: VAS and WOMAC pain Behavioural recovery: WOMAC function, Barthel Index Negative affect: PANAS Length of stay: days in hospital
Notes	Author was not contacted as insufficient time prior to analysis
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	p465: "at preadmission, patients were allocated randomly into either group A or group B…patients were randomized by age and not by functional status"
Allocation concealment (selection bias)	Unclear risk	No information provided in paper
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Not stated but very unlikely that either patients or staff administering intervention could be blind – involved attending a preoperative hip class
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	No information provided in paper
Incomplete outcome data (attrition bias)   All outcomes	High risk	Four of 35 lost to follow‐up, all from the Intervention group (reducing from 19 to 15). Appear to have retained all 20 in Control group. Concerning that 21% of intervention group dropped out – no information provided as to why
Selective reporting (reporting bias)	High risk	All outcomes were mentioned in Results, although very briefly and only positive findings reported (assume not significant otherwise). However, data were not provided for the negative affect outcome of the review
‘Intention‐to‐treat’	Unclear risk	No information provided in paper
Other bias	Low risk	No other concerns

PERMALINK

Psychological preparation and postoperative outcomes for adults undergoing surgery under general anaesthesia

Rachael Powell

Neil W Scott

Anne Manyande

Julie Bruce

Claus Vögele

Lucie MT Byrne‐Davis

Mary Unsworth

Christian Osmer

Marie Johnston

Abstract

Background

Objectives

Search methods

Selection criteria

Data collection and analysis

Main results

Authors' conclusions

Plain language summary

Summary of findings

Background

Description of the condition

Description of the intervention

Procedural information

Sensory information

Behavioural instruction

Cognitive interventions

Relaxation techniques

Hypnosis

Emotion‐focused interventions

How the intervention might work

Why it is important to do this review

Objectives

Methods

Criteria for considering studies for this review

Types of studies

Types of participants

Types of interventions

Types of outcome measures

Primary outcomes

Secondary outcomes

Search methods for identification of studies

Electronic searches

Searching other resources

Data collection and analysis

Selection of studies

Data extraction and management

Assessment of risk of bias in included studies

Measures of treatment effect

Unit of analysis issues

Dealing with missing data

Assessment of heterogeneity

Assessment of reporting biases

Data synthesis

`Summary of findings' table

Summary of findings for the main comparison. Any intervention compared to control for adults undergoing surgery under general anaesthesia.

Subgroup analysis and investigation of heterogeneity

Sensitivity analysis

Results

Description of studies

Results of the search

2.

Included studies

Excluded studies

Ongoing studies

Studies awaiting classification

Risk of bias in included studies

1.

3.

Allocation

Blinding

Incomplete outcome data

Selective reporting

Other potential sources of bias

Effects of interventions

Findings by outcome

Primary outcomes

1.Postoperative pain

Studies included in meta‐analysis

Methods	Randomized controlled trials
Participants	85 patients with rectal cancer diagnoses due to undergo surgery were randomized. 6 sites in 4 healthcare Trusts in Northern Ireland; recruited January 2009 to May 2010. Age range: 42 to 84; mean age Intervention group: 63.12 (SD 10.69); mean age Controls 68.29 (SD 9.34). 49 (64.5%) male; 27 female
Interventions	Control: usual care (demonstration with stoma appliances, discussion of condition, options and concerns with specialist nurse). Also: "generic colorectal cancer and stoma information leaflets". Behavioural instruction Intervention: usual care as Controls. Also, "guided tour" of pack of 14 leaflets, including "surgery for cancer of the rectum" and "coming into hospital"; specialist nurse’s approach based on Knowles’ Process Model (an approach to education). Procedural information
Outcomes	Negative affect: Hospital Anxiety and Depression Scale (anxiety and depression) after surgery, prior to discharge
Notes	Author provided some information about risk of bias
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	p184: "Randomisation was provided by an independent research secretary, using a computer generated list of random numbers"
Allocation concealment (selection bias)	Low risk	p184: "The SCNS [stoma care nurse specialist] telephoned the randomisation service for an allocation code and assignment to either intervention or control group. Blinding of the researcher as to the random allocation group of participants was used to reduce bias"
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Difficult to see how the SCNS delivering the interventions could have been blind – p184: "the SCNS who delivered either the new information pack intervention) or the information currently provided in usual care (control)" – so the same person did either
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	No information provided in paper
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	p187: at time 2 (post‐surgery, prior to discharge), analysed data for 43 of 47 for primary outcome (satisfaction). The excluded 4 did not receive the intervention (1 withdrew, 3 "randomised too soon"). Control group: analysed data for 33 of 38 for primary outcome. The excluded 5 did not receive the allocation (3 withdrew, 2 "randomised too soon"). In addition, 4 participants "felt unable or unwilling to complete the secondary outcome measures" (p186) – groups not specified. So, in total, 13 participants did not provide data for the outcomes of interest to us – 13 of 85 = 15.3%
Selective reporting (reporting bias)	High risk	Primary and secondary outcomes clearly stated and all outcomes are mentioned in results. Author: also completed the Miller Behavioural Style Scale (but this is unlikely to be an outcome measure). However, no details (e.g. mean, SD) provided for outcomes relevant to review
‘Intention‐to‐treat’	High risk	Flow chart p187: 4 in intervention group and 5 in control group did not receive their allocated intervention and are excluded from analysis. This would suggest carrying out per‐protocol analysis
Other bias	Unclear risk	Found a significant difference for age between groups – mean age in intervention group significantly lower (intervention group mean = 63.12 (SD 10.69); controls: 68.29 (SD 9.34). Also, odd that group size so different after randomization (intervention n = 47; control n = 38) ‐ unclear if randomization was effective in generating comparable groups Also, the SCNS delivering the intervention in each site would become increasingly aware of the essence of the intervention protocol (the tailoring of information using the Knowles Process Model) during the study. There is a risk of cross‐contamination of the intervention into the control condition as the only differences seemed to be in the type of information leaflets (we are not aware how different these were) and the tailoring of information by the SCNS. There is no assessment of intervention fidelity to assess for this potential bias

Methods	Randomized controlled trial: a pilot/feasibility study
Participants	30 frail older adults undergoing total hip arthroplasty in orthopaedic department of the Gelderse Vallej Hospital, Ede, Netherlands (dates not provided). Intervention group mean age 76.9 (SD 6.3); control group mean age 75.0 (SD 6.3). Intervention group: 14 female, 1 male. Control: 10 female, 5 male. Overall: 24 female, 6 male ‐ 80% female
Interventions	Control: usual care – group session 3 weeks preoperative; including information about the operation, walking with crutches and exercises for postoperative phase. Procedural information Intervention: as control group. Also: physical therapists supervised exercise sessions at home 30 minutes/session, twice/week for 3 to 6 weeks. Also exercised by selves (or with help) 4 times/week and aimed to walk a minimum of 30 minutes/day. Training tailored to participant and home environment; intensity and no. repetitions increased over time and functional activities made more challenging. Given pedometer and kept diary. Behavioural instruction. (Note: relaxation was offered in intervention, but only as a treatment option for patients who reported symptoms/pain after training)
Outcomes	Length of stay Behavioural recovery: Iowa Level of Assistance Scale (ILAS), day 4 post‐surgery – ability to function in daily life
Notes	Author provided some information about measures and risk of bias
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	p611: "Participants were randomly assigned to the intervention or control group by a research assistant not associated with the study. Randomization took place after stratification by age…, using prepared envelopes per stratum. Within each stratum a permuted block randomization with a block size of 10 was used"
Allocation concealment (selection bias)	Low risk	Participants were randomized after informed consent, by someone who was not associated with the study (p611)
Blinding of participants and personnel (performance bias)   All outcomes	High risk	p611: "The 2 physical therapists (RHN and CMD) who performed the training and the patients were not blinded to treatment allocation"
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	p611: "outcome assessors (EO and SMA) were" (blinded to treatment allocation)
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	Generally, attrition is well reported but reasons for this are not given for time 2 (T2) – the time of interest to us, but I think not of primary interest to the researchers Intervention group: 1 participant: no surgery (because of co‐morbidities). N for length of stay outcome: 29. Functional mobility score (ILAS) at T2: intervention n = 12; control n = 13. Attrition is low, but sample size is small, and difficult to assess risk of bias without knowing reason for attrition
Selective reporting (reporting bias)	Low risk	No obvious selective reporting but no reference to a protocol document. Data are provided for outcomes of interest to the review. Author: "We had no other outcomes"
‘Intention‐to‐treat’	Low risk	p612: "intention‐to‐treat analyses were used"
Other bias	Low risk	No other concerns

Methods	Randomized controlled trial. Had an additional 4th group containing 10 participants who expressed a preference to receive no information ‐ this group is not detailed here
Participants	Women undergoing abdominal hysterectomy at St George's Hospital, London, July 1980 to June 1981. 60 patients were randomized. Mean age (including the 10 non‐randomized patients): 42, range 27 to 61
Interventions	Attention control: manual describing ward and hospital routines(some procedural information) Intervention 1: information; manual describing procedures and sensations before and after the operation(procedural and sensory information) Intervention 2: cognitive coping. Manual aimed at helping reader provide positive thoughts in response to worry – cognitive reappraisal(cognitive intervention) All: given manual at initial visit; at 2^nd visit day before operation, author checked had read it and discussed to ensure fully understood
Outcomes	Pain ‐ day 3 post‐surgery: 1. Analogue scale; 2. Questions about intensity and frequency. 3. Scaled checklist of 30 pain descriptors Pain – no. times mentioned in nursing record Negative affect: POMS to record mood – day 3 post‐surgery and 3 weeks post‐discharge. Used subscales tension/anxiety, depression, fatigue and vigour Behavioural recovery – diary record – days when undertook 10 household activities – summed across tasks and no. days each was performed Length of stay
Notes	Authors provided additional information about measures, results and risk of bias
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	p274: "proceeded to the next stage, determined by opening a sealed envelope containing the randomly allocated manual". Author: "All booklets were prepared in equal numbers and placed in envelopes...They were shuffled thoroughly. The top five envelopes were carried with me to patient visits. The top booklet in the stack was allocated to a subject during the appropriate visit"
Allocation concealment (selection bias)	Low risk	p274: "proceeded to the next stage, determined by opening a sealed envelope containing the randomly allocated manual". "the manuals were outwardly identical" Author: "no allocations were changed once assigned". Agreed low risk because even though do not specify that envelopes were opaque, the manuals contained were outwardly identical so it would not be possible to determine contents. Should e.g. the envelopes have been dropped and picked up in a different order, this would effectively be a further re‐shuffling ‐ the original randomization process
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Seems likely that participants were blind – all received same rationale "that reading them would help to set patients at their ease" (p274). However, personnel not blind – "all interviews were carried out by one of the authors (VR)" – this included making sure that each participant understood their manual. Possible that VR was blind when presenting the manual, but not at the 2^nd preoperative interview when the manual was discussed
Blinding of outcome assessment (detection bias)   All outcomes	High risk	p273 "all interviews were carried out by one of the authors (VR)". Preoperative interview was part of intervention, so would not be blind to condition
Incomplete outcome data (attrition bias)   All outcomes	Low risk	No attrition was reported. As the authors were careful in reporting those who agreed to be randomized, seems likely that attrition was not reported because it did not occur – but need this to be stated to be certain. Author: "We had no drop‐outs, but four subjects were excluded because it was decided that they would have vaginal hysterectomies at the time of surgery or both ovaries were removed during the abdominal surgery. We thought that both excluded conditions would be too different, given that others with abdominal incisions would perhaps have more abdominal pain. We also thought there could be mood differences when both ovaries were removed. We included those women who had one ovary removed"
Selective reporting (reporting bias)	Low risk	With help from authors and checking of original thesis, obtained mean outcome values, but SDs (or SEs) were not available so would need to impute to enter data into meta‐analysis
‘Intention‐to‐treat’	Low risk	So long as no attrition, intention‐to‐treat is likely because it is unlikely that participants would not have received the intervention to which they were allocated. However, this is not clearly stated. Author: "That [intention‐to‐treat] was not the standard at that time, unfortunately, but was not an issue, I guess, as we had no drop outs and all subjects stayed in the group to which they were randomly assigned"
Other bias	Low risk	No other concerns

Methods	Randomized controlled trial; 4 groups including both usual care and attention controls
Participants	Patients undergoing total knee or hip joint surgery at an orthopaedic hospital in the UK. 200 randomized (data for 118 analysed) ‐ of the 118, mean age = 65.6 years (SD11.4), 50 male, 68 female ‐ 57.6% female. Data collected August 2002 to December 2003
Interventions	Control: usual care (resting 15 to 20 minutes) Attention control: 15 to 20 minutes, asked to describe what do, feel, think when in pain Intervention 1: total body relaxation: 15 to 20 minutes, tensing and relaxing each muscle group; concentrating on feelings while doing this. Received audio cassette of instructions Intervention 2: jaw relaxation: 15 to 20 minutes, lower jaw drops slightly, tongue rests quietly, lips soft; slow, deep breaths All interventions: taught at pre‐admission clinic; asked to practise once/day for 1 week pre‐admission; given written instructions and letter 1 week before admission, reminding participants to practise
Outcomes	Pain: VAS for pain at rest and at movement (only one score reported – not clear if reported score = one of these or combination) Negative affect: state anxiety (short form STAI) Both: 2 to 3 days after surgery
Notes	Point made in Discussion: this group: pain scores reduced by a fairly large amount from before surgery to postoperatively – so the main source of pain had been reduced by the surgery, and pain seen as less of a problem than before. Potential for interventions to reduce postoperative pain may depend on level of pain before Attempted to contact authors; no reply received
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	p683: "Random allocation was concealed by using a system of sequentially numbered, opaque, sealed envelopes containing the computer generated randomly [sic] allocation, which was drawn up by a statistician"
Allocation concealment (selection bias)	Low risk	p683: "Random allocation was concealed by using a system of sequentially numbered, opaque, sealed envelopes containing the computer generated randomly [sic] allocation, which was drawn up by a statistician. These envelopes had to be used in order so that the allocation could not be altered; thus the allocation was secure"
Blinding of participants and personnel (performance bias)   All outcomes	High risk	None reported. It may be that participants were unaware of intervention (especially attention control and the 2 relaxation groups) but it seems that the same researchers were delivering all interventions, and seems unlikely they would not know what they were delivering, so they would have known (p683: "The two researchers teaching the intervention were trained...with a researcher who had extensive experience of teaching relaxation and the techniques used in the attention control")
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	For postoperative, post‐intervention outcomes: "post‐intervention data were collected using a self‐administered questionnaire completed by participants and put in a sealed envelope whilst the researcher was out of the room" (p684)
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	p683: No. lost from each group: usual care: 20, attention control: 20; jaw relaxation: 18; total body relaxation: 24 Reasons for loss: surgical date changed (n = 25); researcher unavailable (15); surgery postponed to after study closure (4), surgical plan changed so not eligible (10); withdrew because too ill/too much pain (18); did not wish to continue (10). Reasons not provided by group
Selective reporting (reporting bias)	Unclear risk	It is not stated whether pain measure reported in results is at rest, on movement, or combination of both (so not clear whether one is unreported) Anxiety VAS – findings not reported – it may be that they used the VAS for post‐intervention outcomes rather than pre‐intervention but unclear
‘Intention‐to‐treat’	Unclear risk	No information provided in paper
Other bias	Unclear risk	Pre‐admission data may have been collected after random allocation. This might affect the baseline for change scores

Methods	Randomized controlled trial + tested effects of the moderators External Health Locus of Control and Self‐Efficacy
Participants	90 participants undergoing coronary artery bypass surgery in Queensland, Australia were randomized (data analysed for 80) (dates not provided). Overall sample: mean age 65.5 (SD 9.2, range 41 to 85); 64 (80% male), 16 female. Intervention mean age 65.1 (SD 9.8); control mean age 66.1 (SD 8.5). Intervention: 22 (of 37) male; control: 31 (of 43) male
Interventions	Control: standard care Intervention: day before surgery, 30‐minute semi‐structured interview: building rapport, eliciting patient concerns, posting questions about surgery and linking the questions with patient concerns. Intended to address cognitive coping strategies, reframing where appropriate (cognitive intervention)
Outcomes	Negative affect: distress (Depression, Anxiety and Stress Scales) Pain: 10 cm VAS Both: at discharge (4 days post‐surgery)
Notes	Could not locate author
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	p186: "Participants were randomized to preparation or standard care conditions"
Allocation concealment (selection bias)	Unclear risk	No information
Blinding of participants and personnel (performance bias)   All outcomes	High risk	p186: "In keeping with the single‐blind control group design, the RA administered all inventories, and the data produced and assignments were not revealed to patients, the psychologists, or other hospital staff until the conclusion of the study. The RA advised the psychologist only of the number of consenting patients who completed baseline measures and were assigned to the preparation condition for purposes of preparation arrangement." (RA = research assistant). However, the psychologist would have known when they were providing the intervention – for the patient, this would depend on the information provided (and whether they talked to other patients)
Blinding of outcome assessment (detection bias)   All outcomes	High risk	The RA who did the outcome assessments also did the randomization
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	p185: "10 patients did not complete questionnaires and/or provide sufficient blood (1 patient was deceased before posttest)" Attrition not provided by group unfortunately p186: "male patients missed more responses than female patients…and there were fewer missing response among patients who received the preparation". p185: "missing data did not exceed 5% and were replaced by group means"
Selective reporting (reporting bias)	High risk	It was not clear which measures were assessed at baseline, and which at discharge, however results reported for those measures one would expect to have been measured as outcomes only. Very little detail presented for some outcomes (e.g. ns direct effects). However, no clear evidence of selective reporting – but no reference of a protocol to which to refer. Means and SDs for outcomes not provided by group so cannot enter into meta‐analysis
‘Intention‐to‐treat’	Unclear risk	No information provided in paper
Other bias	Unclear risk	No other concerns

Methods	Cluster‐randomized, controlled trial
Participants	45 adults undergoing total hip arthoplasty at the Military Medical Academy, Belgrade, Serbia (dates not provided). Intervention group (n = 23): mean age 60.05 (SD 11.01, median 62.5, range 30 to 70). Controls (n = 22): mean age 56.2. (SD: 18.45, median 66.5, range 19 to 70). Intervention, 14 female; control: 16 female. Unclear whether these figures relate to no. analysed (20 in each group) or numbers randomized (23 and 22 respectively). See Table 1, p294
Interventions	Control: Author: both groups: "standard preparatory information" from surgeons and anaesthesiologists Intervention: 1 appointment with "physiatrist" (conversation and brochure: information re. operation and rehabilitation); 2 practical sessions with physiotherapists (instructed to perform exercises and basic activities e.g. bed mobility, standing and walking with crutches, toilet use, sitting on chair, walking). Behavioural instruction; procedural information
Outcomes	Pain at rest and movement: VAS at discharge Length of stay
Notes	Some behavioural recovery measures were taken but not included as judgements required and no psychometric information Author provided additional information regarding control/intervention conditions, measures, data and risk of bias
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	p292: "patients were randomly divided into two groups". Author: "Orthopedics department has three units. Most hospital rooms are three ‐ bed rooms. We thought that the patients from the control and study group should not reside in one room at the same time. Also, the patients might have met in the dining room and the hallway of the unit. There was the possibility that the patients from the study and control groups exchange knowledge of preoperative physical therapy and education. So, in order to perform this study, we had to separate the groups spatially. The research team could not influence the distribution of patients admitted to the three units. The patient was admitted to the unit in which an orthopedic surgeon, who planned the operation and who performed arthroplasty worked. So, randomization was performed by drawing the unit where patients will be included in the preoperative physiotherapy and education." So, cluster‐randomized
Allocation concealment (selection bias)	Unclear risk	No information provided in paper
Blinding of participants and personnel (performance bias)   All outcomes	High risk	No blinding reported. Very unlikely intervention blinded – as involved attending/giving 1 appointment and 2 practical classes (p293)
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	No information in paper. Author: "One therapist was conducting preoperative physical therapy, and a physiatrist conducted the education. They did not participate in the evaluation of outcome. Therapists who were carrying out post ‐ operative physical therapy in all three units were not introduced to a random in its units. They performed the outcome assessment. But I'm not sure whether a double blind study was provided. Specifically, during rehabilitation, the patient from the study group and therapist could talk about the preoperative physical therapy"
Incomplete outcome data (attrition bias)   All outcomes	Low risk	Attrition detailed (e.g. flow chart p293) – low numbers lost, reasons given – unlikely to bias findings No./% participants lost to follow‐up: 5 (11.11%). 3 from intervention group; 2 from control group – because of "intraoperative and postoperative complications" (p293). Further detail p204: during operation: 1 fracture of proximal femur; 1 fracture of acetabulum cavity) postoperative complications: 1 participant hip dislocation; 1 epileptic seizure; 1 gastrointestinal disorder)
Selective reporting (reporting bias)	Low risk	A lot of measures are reported ‐ however, the 10 behaviours were assessed daily but only reported at day 3 and at discharge – not stated why those particular days. When contacted, the authors provided a high level of detail on some measure that were not included in the report. The level of openness, especially as some of the non‐reported findings were highly significant, suggests that the authors were not selectively reporting significant findings
‘Intention‐to‐treat’	Low risk	No other concerns
Other bias	Low risk	Intention‐to‐treat seems likely as numbers consistent throughout study – but not stated. However, taking author information that allocated and treated by unit seems unlikely patients would have changed groups. Author: "Statistical analyses did not include data of the patients who were excluded due to intra‐and postoperative complications"

Methods	Randomized controlled trial (a pilot study)
Participants	50 participants randomized ‐ undergoing first CABG (data collected for 45) at a university‐affiliated teaching hospital, Toronto, Canada (dates not provided). `Average' age 61. Control group mean (SD) age: 60.13 (11.0); Intervention 1: 64.18 (7.44); Intervention 2: 57.06 (9.86). Most: male (unclear whether 5 or 11 female, p50)
Interventions	Control: routine "education" – booklet and videotape 2 to 7 days pre‐operation; general information about surgery, postoperative care, recovery (procedural information) Intervention 1: as control plus additional booklet: importance of pain relief, how and when to ask for help; pain‐relief methods; addresses common concerns that prevent asking for help (procedural information (as controls);behavioural instruction, cognitive intervention Intervention 2: as Intervention 1 plus interview with research nurse – discussed points in booklet, answered questions (components as for Intervention 1)
Outcomes	Pain: MPQ‐SF, present pain intensity and numerical rating scale (worst pain last 24 hours). 3 and 5 days post‐surgery Length of Stay
Notes	Author provided some information about risk of bias
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	p46: "using a table of random numbers"
Allocation concealment (selection bias)	Unclear risk	No information
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Research staff were blinded but seems likely participants would have known – and the research nurse who carried out the interviews in the second intervention group would know. So, the blinding would have affected outcome assessment rather than knowledge of intervention for participants and those providing intervention
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	p46: "Data were collected by a blinded research assistant"; p47: "to maintain blinding of the research assistant and staff, all patients received an envelope…the two intervention groups also received the booklet Pain Relief After Surgery"
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	States that 50 participants enrolled; data from all 3 time points (including baseline for 45 – "five of the fifty consenting patients who completed baseline measures were too ill or tired after surgery to complete all measures" (p47). Then confusing as states control n = 16, intervention 1 n = 15, intervention 2 n = 16; data from 45 because 2 patients in intervention 1 were too ill to participate after surgery. Therefore, unclear what happened with the other 3 of the 50 participants who did not complete data – which groups were they in?
Selective reporting (reporting bias)	High risk	Did not report detail of all measures described in Methods and not explained why; some of these relevant to review (NRS means and SDs not presented) ‐ hence high risk. However, for NRS scores did report findings being non‐significant, which suggests this was either error/word space limits rather than selective reporting (p50/51). Author: reported no outcomes measured that were not reported
‘Intention‐to‐treat’	Low risk	p49: "The intention‐to‐treat principle (Newell 1992) was maintained so that individuals randomized to the intervention group were included in this group even if they did not read the booklet"
Other bias	Low risk	No other concerns

Methods	Randomized controlled trial; Note: no `control' group ‐ appear to be comparing 2 interventions
Participants	12 patients undergoing cholecystectomy at 2 hospitals at different locations in the USA (dates not provided). Mean age: 53.5 (range 30 to 70 years); 6 male and 6 female
Interventions	Control: preoperative "instruction" including "objective information", description of sensations and practice of deep breathing, coughing, moving in bed. 45 to 70 minutes (both groups: same time distribution. Sensory information; behavioural instruction Intervention: do not seem to receive control preparation. Preoperative relaxation training session including focusing on breathing and contraction and relaxation of abdominal muscles while receiving EMG feedback from muscles. Also a "5‐minute exercise adapted from Jacobson (1938)" (Jacobsen 1938) – no further information. Goal: reduce both physiological and psychological factors that contribute to pain. Relaxation
Outcomes	Pain – rated on 10 cm line on evening on day of surgery, and days 1 and 2 post‐surgery
Notes	Attempted to contact authors; no reply received
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	p237: "The subjects were randomly assigned to one of the two conditions"
Allocation concealment (selection bias)	Unclear risk	No information provided in paper
Blinding of participants and personnel (performance bias)   All outcomes	High risk	It appears that someone was present with the intervention conditions at least, so blinding of the person conducting the intervention unlikely (high risk). Unclear for participants – depends on information given
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	Outcome measures were collected "by an uninformed assistant" (p237) – this seems to imply blinded but not entirely clear
Incomplete outcome data (attrition bias)   All outcomes	Low risk	No attrition reported and no. reported in analysis matches no. randomized
Selective reporting (reporting bias)	Unclear risk	Means and SDs for relevant outcome measures reported. No measures mentioned in introduction or methods that were not reported, but no reference to a protocol document, and looked at some outcomes that were not mentioned in Methods
‘Intention‐to‐treat’	Unclear risk	No information provided in paper
Other bias	Unclear risk	Some concern about selection – "Purposive and convenience sampling were used" (p237) – there is therefore potential for biases related to selection but insufficient information to determine whether likely to be a problem

Methods	Randomized controlled trial (note: actually compared 2 interventions rather than having attention or no treatment control)
Participants	64 patients undergoing total knee arthroplasty at an academic hospital, Maastricht, Netherlands (January 1991 to March 1992). Mean age 65 (range 42 to 85); 48 (75%) female; 16 male
Interventions	No control group Intervention 1: 30‐minute group session; "preoperative instruction" – explained peri‐ and postoperative phase; information about inserting hip replacement and clinical and post‐clinical course of the operation. Procedural information Intervention 2: exercise: strengthening exercises, exercises to prevent thrombosis and gait training with crutches. Behavioural instruction
Outcomes	Pain: VAS where 100 = worst pain. Timing: 2, 5, 7, 10, 14 days post‐surgery and discharge
Notes	Could not locate author
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information: "The patients were divided without pre‐stratification at random into two groups. Matching took place with respect to the group size"
Allocation concealment (selection bias)	Unclear risk	No information provided in paper
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Instruction groups ‐ 2 physiotherapists (who were also present in exercise group) so personnel were not blind
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	No information provided in paper
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	Some attrition ‐ from 64 to 57. N at each time point is not always clear; allocation to each group (31 to instruction; 33 to exercise) is given only in Abstract At day 7 – 63 patients? At day 10 – 62; 30 instructed, 32 non‐instructed. At day 14 – 57; 28 instructed, 29 non‐instructed
Selective reporting (reporting bias)	High risk	Mean (SD) not reported for pain outcome (in general, in paper, only reported for significant findings)
‘Intention‐to‐treat’	Unclear risk	No information provided in paper
Other bias	Low risk	No other concerns

Methods	Randomized controlled trial, also looked for interaction effects by levels of patient "fear", "denial" and "aggressiveness"
Participants	78 patients undergoing hysterectomy (analysed n = 37) or cholecystectomy (analysed n = 33, 26 (79%) female) at a 550‐bed community hospital serving suburban and rural population in Michigan, USA (dates not provided)
Interventions	Control: usual care; visit by anaesthesiologist and surgeon; discussion by nurses re. deep breathing and coughing after surgery. Hysterectomy patients: offered lecture on hospital procedures (behavioural instruction; procedural information (hysterectomy only)) Intervention 1: Information: 9‐minute taped message "describing sensations and procedures likely to be experienced". Procedures e.g. skin preparation, IV infusion, postoperative diet. Sensations e.g. feeling in incision. Also usual care (sensory information, procedural information, usual care components) Intervention 2: Relaxation: 25‐minute tape, used once evening before surgery and could use as often as wished postoperatively. Focused attention on individual muscle groups and relaxed those muscles. Counting task. Relaxation (and usual care components) Intervention 3: Information and relaxation – components as usual care, information and relaxation All interventions: night before surgery
Outcomes	Length of stay
Notes	Author provided additional details regarding interventions, outcome data and risk of bias
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	p82: "Patients were randomly assigned to one of four groups, stratified according to type of operation". Author: "I used the random number table in the back of the Guilford statistics book to create the sequence"
Allocation concealment (selection bias)	Unclear risk	No information in paper. Author: "Only after consent would the treatment condition be known by the interviewers"
Blinding of participants and personnel (performance bias)   All outcomes	High risk	"Physicians and nursing personnel were not informed of the distribution of patients among treatment conditions" (p83) but seems likely patients and those delivering interventions would not be blind. Author: "relaxation patients would have a tape recorder by their bed. Controls and Information only patients would not have a recorder. Controls received a tape describing only procedural information and not sensory information"
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	"Physicians and nursing personnel were not informed of the distribution of patients among treatment conditions" (p83). However, does not state whether the interviewer collecting outcome data was blind. RP: "Were the staff recording outcomes (e.g. length of stay) blind to the group allocation of participants?" Author: "yes"
Incomplete outcome data (attrition bias)   All outcomes	Low risk	No./% participants lost to follow‐up: 8 (10.3%). p82: 7 had more intensive surgery than planned or hospitalized for further diagnostic tests – not included because recovery pattern would be atypical. 1 withdrew because she did not wish to complete the questionnaires about recovery. (Assuming she withdrew after randomization). Attrition not stated by group. However, group sizes: 18, 17, 17, 18 suggest that attrition is likely to be evenly spread. Authors confirmed attrition across group: 2 controls, 3 information, 2 relaxation, 1 information and relaxation
Selective reporting (reporting bias)	Low risk	No outcomes stated in Methods that were not reported in Results but no reference to a protocol. When asked whether any outcomes were measured but not reported, author response: "no". Length of stay means and SDs provided but adjusted for age, type of operation and coping ability score; unclear re. how would use in meta‐analysis. Author later sent all means and SDs for length of stay so now possible to include in meta‐analysis
‘Intention‐to‐treat’	Low risk	No information in paper. RP: "Were participants kept in the intervention groups to which they were randomised, regardless of the intervention they received? (i.e. were data analysed according to intention‐to‐treat?)" Author: "yes"
Other bias	Low risk	No other concerns