Non‐pharmacological interventions for assisting the induction of anaesthesia in children

Anne Manyande; Allan M Cyna; Peggy Yip; Cheryl Chooi; Philippa Middleton

doi:10.1002/14651858.CD006447.pub3

. 2015 Jul 14;2015(7):CD006447. doi: 10.1002/14651858.CD006447.pub3

Non‐pharmacological interventions for assisting the induction of anaesthesia in children

Anne Manyande ¹, Allan M Cyna ^2,^✉, Peggy Yip ³, Cheryl Chooi ^2,⁴, Philippa Middleton ⁵

Editor: Cochrane Anaesthesia Group

PMCID: PMC8935979 PMID: 26171895

Abstract

Background

Induction of general anaesthesia can be distressing for children. Non‐pharmacological methods for reducing anxiety and improving co‐operation may avoid the adverse effects of preoperative sedation.

Objectives

To assess the effects of non‐pharmacological interventions in assisting induction of anaesthesia in children by reducing their anxiety, distress or increasing their co‐operation.

Search methods

In this updated review we searched CENTRAL (the Cochrane Library 2012, Issue 12) and searched the following databases from inception to 15 January 2013: MEDLINE, EMBASE, PsycINFO and Web of Science. We reran the search in August 2014. We will deal with the single study found to be of interest when we next update the review.

Selection criteria

We included randomized controlled trials of a non‐pharmacological intervention implemented on the day of surgery or anaesthesia.

Data collection and analysis

At least two review authors independently extracted data and assessed risk of bias in trials.

Main results

We included 28 trials (2681 children) investigating 17 interventions of interest; all trials were conducted in high‐income countries. Overall we judged the trials to be at high risk of bias. Except for parental acupuncture (graded low), all other GRADE assessments of the primary outcomes of comparisons were very low, indicating a high degree of uncertainty about the overall findings.

Parental presence: In five trials (557 children), parental presence at induction of anaesthesia did not reduce child anxiety compared with not having a parent present (standardized mean difference (SMD) 0.03, 95% confidence interval (CI) ‐0.14 to 0.20). In a further three trials (267 children) where we were unable to pool results, we found no clear differences in child anxiety, whether a parent was present or not. In a single trial, child anxiety showed no significant difference whether one or two parents were present, although parental anxiety was significantly reduced when both parents were present at the induction. Parental presence was significantly less effective than sedative premedication in reducing children's anxiety at induction in three trials with 254 children (we could not pool results).

Child interventions (passive): When a video of the child's choice was played during induction, children were significantly less anxious than controls (median difference modified Yale Preoperative Anxiety Scale (mYPAS) 31.2, 95% CI 27.1 to 33.3) in a trial of 91 children. In another trial of 120 children, co‐operation at induction did not differ significantly when a video fairytale was played before induction. Children exposed to low sensory stimulation were significantly less anxious than control children on introduction of the anaesthesia mask and more likely to be co‐operative during induction in one trial of 70 children. Music therapy did not show a significant effect on children's anxiety in another trial of 51 children.

Child interventions (mask introduction): We found no significant differences between a mask exposure intervention and control in a single trial of 103 children for child anxiety (risk ratio (RR) 0.59, 95% CI 0.31 to 1.11) although children did demonstrate significantly better co‐operation in the mask exposure group (RR 1.27, 95% CI 1.06 to 1.51).

Child interventions (interactive): In a three‐arm trial of 168 children, preparation with interactive computer packages (in addition to parental presence) was more effective than verbal preparation, although differences between computer and cartoon preparation were not significant, and neither was cartoon preparation when compared with verbal preparation. Children given video games before induction were significantly less anxious at induction than those in the control group (mYPAS mean difference (MD) ‐9.80, 95% CI ‐19.42 to ‐0.18) and also when compared with children who were sedated with midazolam (mYPAS MD ‐12.20, 95% CI ‐21.82 to ‐2.58) in a trial of 112 children. When compared with parental presence only, clowns or clown doctors significantly lessened children's anxiety in the operating/induction room (mYPAS MD ‐24.41, 95% CI ‐38.43 to ‐10.48; random‐effects, I² 75%) in three trials with a total of 133 children. However, we saw no significant differences in child anxiety in the operating room between clowns/clown doctors and sedative premedication (mYPAS MD ‐9.67, 95% CI ‐21.14 to 1.80, random‐effects, I² 66%; 2 trials of 93 children). In a trial of hypnotherapy versus sedative premedication in 50 children, there were no significant differences in children's anxiety at induction (RR 0.59, 95% CI 0.33 to 1.04).

Parental interventions: Children of parents having acupuncture compared with parental sham acupuncture were less anxious during induction (mYPAS MD ‐17, 95% CI ‐30.51 to ‐3.49) and were more co‐operative (RR 1.59, 95% CI 1.01 to 2.53) in a single trial of 67 children. Two trials with 191 parents assessed the effects of parental video viewing but did not report any of the review's prespecified primary outcomes.

Authors' conclusions

This review shows that the presence of parents during induction of general anaesthesia does not diminish their child's anxiety. Potentially promising non‐pharmacological interventions such as parental acupuncture; clowns/clown doctors; playing videos of the child's choice during induction; low sensory stimulation; and hand‐held video games need further investigation in larger studies.

Plain language summary

Non‐pharmacological interventions for assisting the induction of anaesthesia in children

Background

The initial process of giving general anaesthesia (i.e. induction of anaesthesia) to children can be distressing for them and their parents. Children can be given a sedative medicine (premedication) to drink such as midazolam before anaesthesia is induced in order to help the child relax. However these drugs can have undesirable effects, such as possible airway obstruction before anaesthesia begins and during recovery. In addition behaviour changes may occur after the operation. Some non‐drug alternatives have been tested to see if they could help children relax and co‐operate at the beginning of their anaesthesia. This review aims to assess the effects of non‐drug interventions such as hypnosis, acupuncture and video games in helping with the beginning of general anaesthesia in children

Key findings

We included 28 trials (2681 children under the age of 18 years and or their parents) with a large number of interventions (17) assessed.

The presence of parents at induction of the child's anaesthesia has been the most commonly investigated intervention (eight trials), but has not been shown to reduce anxiety or distress in children, or increase their co‐operation during induction of anaesthesia.

Although parents should not be actively discouraged from being present if they prefer to do so, equally parents should not be encouraged to be present at their child's induction if they prefer not to do so.

Most commonly other interventions are given to the child (e.g. video games or hypnosis) but sometimes the intervention is given to the parent. One study of acupuncture for parents found that the parent was less anxious, and the child was more co‐operative, at induction of anaesthesia. Another study of giving parents information, in the form of pamphlets or videos, failed to show an effect. In other studies looking at interventions for children, clowns or clown doctors, a quiet environment, video games and computer packages (but not music therapy) each showed benefits such as improved co‐operation in the children.

Quality of the evidence

Many of the studies were of poor quality and too small to provide clear answers to the study question. However potentially promising non‐pharmacological interventions such as parental acupuncture; clowns/clown doctors; playing videos of the child's choice during induction, pre‐operative hypnosis and hand‐held video games require further testing in future studies. Non‐drug interventions that might help parents relax need further study, as there is some evidence that more relaxed parents may improve their child's anaesthesia induction experience.

Summary of findings

Background

The initial introduction of a general anaesthetic is known as 'the induction of anaesthesia' and can be stressful for children. Disrupted routines, unfamiliar faces, separation from family, hospital procedures and uncertainty about anaesthesia or surgery can be harrowing for patients (Brennan 1994; Feldman 1998). Minimizing anxiety and distress at the time of anaesthetic induction may therefore reduce adverse psychological and physiological outcomes (Greenberg 1996; Holm‐Knudsen 1998).

Induction of anaesthesia   General anaesthesia may be induced by inhaled or intravenous routes, although the former is most often used for children. Some anaesthetists believe that a mask or inhalational induction is less psychologically terrifying to children (Aguilera 2003), since children are generally thought to have a fear of needles (Van den Berg 2005a; Van den Berg 2005b). Inhalational anaesthesia is induced with a volatile agent in air or nitrous oxide mixed with supplemental oxygen, usually through a breathing circuit (tubing attached to a face mask).

Distress and anxiety in children undergoing anaesthesia   Most children find induction of general anaesthesia before surgery very stressful (Kain 2005; Wollin 2003), and parental stress can be easily transmitted indirectly to a child (Bevan 1990). The level of a child's anxiety varies with age, maturity, temperament and previous anaesthetic experiences (Davidson 2006; Stargatt 2006). A previously co‐operative child may become apprehensive and resist the application of the mask on their face or become upset when the anaesthetic circuit is brought close to them. Children may protest, fight or try and escape during this period (Greenberg 1996), which may prolong the induction and be emotionally traumatic for the child, parents and theatre staff (Holm‐Knudsen 1998; Iacobucci 2005; Kain 1999b). Preoperative distress has also been found to be associated with postoperative agitation and negative behaviours (Stargatt 2006). The consequences of preoperative anxiety and distress may extend beyond the perioperative period (Kain 1996a; Kotiniemi 1997).

Pros and cons of premedication   Sedative medications can alleviate preoperative anxiety, facilitate separation from relatives or friends, and reduce distress at induction (Kain 1999a). However, children may refuse the drug, the drug may fail or even cause adverse reactions such as disinhibition and dysphoria, postoperative behavioural changes and prolonged recovery times (Ullyot 1999). Other disadvantages include safety concerns (airway obstruction or respiratory depression in unmonitored situations); costs of pharmacy; additional nursing staff and equipment; list delays; and delayed discharge (Cray 1996). As a result non‐pharmacological methods have been sought.    Interventions  A wide range of non‐pharmacological interventions have been used to reduce perioperative distress and encourage co‐operation in children. These can be broadly categorized as:

psychological (cognitive or behavioural);
environmental;
equipment modification;
social interventions, including communication.

Rationale for the review

Previous systematic reviews have examined the effects of patient education on preoperative anxiety (Lee 2003; Lee 2005) and the effect of preoperative fasting on perioperative complications in children (Brady 2009). A Cochrane review (Uman 2013) has evaluated psychological interventions for needle‐related procedures in children and adolescents, which includes patients presenting for intravenous induction of anaesthesia. Another Cochrane review (Pillai Riddell 2011) has investigated non‐pharmacological interventions for needle‐related procedural pain in neonates and infants.

There has been no comprehensive, systematic review of the effects of non‐pharmacological interventions administered in hospital to assist the induction of anaesthesia in children. In addition, information about which particular interventions or combinations of interventions are most effective in this setting has not been assessed. This is an update of the 2009 version of this review (Other published versions of this review).

Objectives

To assess the effects of non‐pharmacological interventions in assisting induction of general anaesthesia in children by reducing their anxiety, distress or increasing their co‐operation.

Methods

Criteria for considering studies for this review

Types of studies

We included randomized or quasi‐randomized controlled trials.

Types of participants

We included children or adolescents aged less than 18 years presenting for induction of general anaesthesia, except where the intent is solely intravenous induction.

Types of interventions

We included any non‐pharmacological intervention implemented on the day of surgery compared with any other intervention, such as a midazolam premedication, or no treatment. Studies may assess a single non‐pharmacological intervention or a combination of non‐pharmacological interventions, and may compare them with other non‐pharmacological interventions; pharmacological interventions (e.g. midazolam or ketamine premedication); or with usual care.

We included the following types of interventions:

psychological (cognitive or behavioural) interventions: such as distraction, cognitive tasks, hypnosis, virtual reality;
environmental interventions: use of induction room, patient retains own clothing;
equipment modification: disguised anaesthesia delivery system;
social interventions: parental or support person presence, number of medical staff in the room at induction;
anaesthetist communication: tone of voice, language (neutral or positive).

We considered interventions with parents or accompanying persons if the child's anxiety, distress or co‐operation at induction were outcome measures.

Types of outcome measures

Primary outcomes

The number of children with distress or anxiety, or the extent of presence or absence of distress or anxiety (as defined and measured by the authors of the study) during induction of general anaesthesia;
The number of children who co‐operate, or the extent of presence or absence of co‐operation (as defined and measured by the authors of the study) during induction of general anaesthesia.

Secondary outcomes

The number of caregivers with anxiety (as defined and measured by the authors of the study);
The time taken for anaesthetic induction;
Change from planned inhalational to intravenous (iv) induction;
The number of children with increased anaesthetic requirements;
Risk of emergence delirium;
The number of children with negative behavioural changes (as defined and measured by the authors of the study) in the immediate postoperative period (while the child is in recovery) e.g. distress in recovery;
The number of children co‐operating or without distress on entering the room, or area, where anaesthesia induction is to take place (as defined and measured by the authors of the study);
The number of children or caregivers satisfied with care (as defined and measured by the authors of the study).

Outcome Measures

We defined these as any type of negative affect or behaviour associated with the induction of anaesthesia (e.g. anxiety, stress, fear, unco‐operative behaviour) which can be assessed by psychological measures of behaviour, anxiety or distress such as the Yale Preoperative Anxiety Scale for measuring anxiety in young children (Kain 1997); the Induction Compliance Checklist for assessing co‐operation during induction (Kain 1998); and the Vernon Post Hospitalization Behavior Questionnaire (Stargatt 2006).These scales may provide a measure of the extent of anxiety or distress.

Search methods for identification of studies

Electronic searches

We searched the Cochrane Central Register of Controlled Trials (CENTRAL,the Cochrane Library 2013, Issue 1, see Appendix 1). We also searched the following complementary medicine, nursing, psychology and medical databases: MEDLINE (Ovid SP, 1966 to January 15, 2013, see Appendix 2), EMBASE (Ovid SP, 1980 to January 15, 2013, see Appendix 3), PsycINFO (Ovid SP, 1995 to January 15, 2013, see Appendix 4), CINAHL (EBSCO host, 1982 to January 2, 2012, see Appendix 5), Dissertation Abstracts (1988 to 14th December 2008), and ISI Web of Science (1990 to January 15, 2013, see Appendix 6), and reran the searches on 28 August 2014.

The original search was performed on 14th December 2008 (Yip 2009).

We searched MEDLINE using the MeSH headings and text words and adapted this strategy for the other databases as appropriate.

After piloting various search strategies, we largely omitted terms to describe the possible interventions, since our piloting revealed that such interventions were not always indexed, or indexed consistently.

We searched registers of ongoing trials such as the Meta‐Register of Trials (www.controlled‐trials.com).

Searching other resources

We located additional references by searching the reference and citation lists of relevant papers and adjusted our search strategy accordingly.

We searched for unpublished studies and dissertations for possible inclusion in this review by contacting researchers through email list‐servers such as the Paediatric Anaesthesia Conference (PAC) list‐server; the Society of Pediatric Psychology list‐server; and by contacting experts and trialists through e‐mail and direct communication.

We did not limit the search by language or publication status.

Data collection and analysis

Selection of studies

We reviewed the titles and abstracts of studies identified from the search. From the full text of potentially relevant articles, four review authors (PM, AM, PY, AVC) independently assessed each trial for inclusion in terms of population, intervention, outcome, and study design. We resolved disagreements regarding inclusion of potentially eligible studies by consensus or third author arbitration (AMC).

We excluded studies:

of prehospital preparation programmes (hospital tours, modelling, stress‐point preparation);

of non‐hospital settings;

of patient education or media‐based interventions prior to the day of surgery which have been addressed elsewhere (Lee 2003; Lee 2005);

assessing the effects of non‐pharmacological interventions to assist with intravenous induction of anaesthesia, as this is being considered elsewhere (Uman 2013; Pillai Riddell 2011);

assessing the effects of fasting preoperatively as this is being considered elsewhere (Brady 2009).

Data extraction and management

At least two review authors independently extracted the following data (using a form designed for this specific review):

study participants: age, gender, previous anaesthetics, inclusion and exclusion criteria;
study methods: objective, design, randomization, recruitment, blinding (participant, assessor, other staff, statistician), methods of analysis, follow‐up;
interventions: intervention type, timing (when intervention used), co‐interventions, control (usual care description);
outcomes: outcome type, author's definition of outcome, measurement tool (including validity), timing of assessment;
results: means, standard deviations, numbers of events, proportions;
study withdrawals or losses to follow‐up, with reasons.

We contacted one study author to clarify information and provide additional data. When we had completed the data extraction forms, two review authors entered the data into Review Manager 5 software (RevMan 5.3) and a third review author checked them.

Assessment of risk of bias in included studies

Four authors (PM, AM, PY, AVC) independently examined the methodological quality of trials in relation to randomization; allocation concealment; outcome assessment; blinding of outcome assessments; losses to follow‐up and treatment of withdrawals. We graded each item as 'low risk', 'high risk' or 'unclear'; or gave actual numbers in the case of losses to follow‐up. Due to the nature of the interventions, such as parental presence, blinding of the interventions was not possible. We therefore included studies without blinding of individuals administering and receiving interventions for inclusion.

Measures of treatment effect

In studies that reported dichotomous data, we calculated risk ratios (RRs) with 95% confidence intervals (CIs). For continuous outcomes (such as anxiety) we calculated mean differences (MDs) and 95% CIs or standardized mean differences (SMDs). When scales of outcomes are in different directions (e.g. scales with a low score for low anxiety and others with a high score for low anxiety), we subtracted means from the highest value in the scale. We analysed outcomes such as anxiety, distress and co‐operation using mean differences where possible.

Assessment of heterogeneity

We estimated heterogeneity using the I² statistic (Higgins 2002). Where there was moderate heterogeneity (I² > 50%) we presented data with a random‐effects model.

Assessment of reporting biases

We attempted to assess possible publication bias by visual inspection of funnel plots, with asymmetry of the funnel plots indicating possible publication bias.

Data synthesis

We synthesized and analysed data using RevMan 5.3.

Subgroup analysis and investigation of heterogeneity

We had planned to conduct subgroup analyses to compare:

different age groups such as: infant or toddler (0 to 2 years), children (3 to 12 years) and adolescent (3 to 17 years);
inhalational and intravenous methods of induction (for studies where both methods have been used);
whether the outcomes were measured at the time of induction, before induction or after induction.

However there were insufficient data to do this.

Sensitivity analysis

We had intended to perform the following sensitivity analyses, but there were insufficient data to complete this:

for randomized and quasi‐randomized trials;
for trials with and without clear allocation concealment;
in trials where anaesthetic agents at induction are controlled and not controlled for.

Results

Description of studies

Results of the search

The original review (Yip 2009) included 17 trials. We included 11 new trials for this update of the review, making a total of 28 included trials. We reran the search in August 2014. We will deal with the single study found to be of interest when we next update the review. (see Figure 1).

Study flow diagram of literature search results for this review UPDATE only (results not available for earlier version of the review Yip 2009). We reran the search in August 2014. *We will deal with the single study of interest found when we update the review.

Included studies

The 28 included trials investigated 17 comparisons involving 2681 children or their parents, or both. See Characteristics of included studies for detailed descriptions.

Settings

Fifteen of the trials were conducted in the United States of America; seven in Europe; two in the UK, one in Japan, two in Turkey, and two in Canada.

Interventions

Of the 28 included trials, 12 trials primarily addressed parental presence (four new trials for this update); 13 addressed child or child/parent interventions (seven new trials for this update); and three addressed parental interventions, with some trials addressing more than one area.

Parental presence

parental presence versus no parental presence (Akinci 2008; Arai 2007; Bevan 1990; Kain 1996b; Kain 1998; Kain 2000; Kain 2003; Kain 2007; Palermo 2000; Wright 2010);
one parent versus two parents (Kain 2009);
parental presence versus sedative premedication (Arai 2007; Kain 1998; Kain 2007; Kazak 2010);
parental presence plus sedative premedication versus no parental presence (Kain 2003).

Child or child/parent interventions

Passive:
- video viewing ‐ induction room 'fairytale' (Berghmans 2012);
- video clips (streamed) (Mifflin 2012);
- low sensory stimulation (Kain 2001);
- music therapy (Kain 2004);
introduction/exposure to mask (MacLaren 2008);
Interactive:
- cartoon and interactive computer package preparation (Campbell 2005);
- video games (Patel 2006);
- clown doctors/clowns (Fernandes 2010; Golan 2009; Meisel 2009; Vagnoli 2005; Vagnoli 2010);
- hypnosis (Calipel 2005);

Parent interventions

parental acupuncture (Wang 2004);
parental video (McEwen 2007; Zuwala 2001);

Some trials in which parental presence was not the primary focus of the intervention controlled for this factor by having parents present (Campbell 2005; McEwen 2007; Patel 2006; Vagnoli 2005; Wang 2004; Wang 2005; Zuwala 2001; Vagnoli 2010); or not present (Kain 2004; Kain 2001; Wang 2008) during the induction of anaesthesia. One trial did not control for parental presence (Calipel 2005) and one trial used parents as a rescue intervention for anxiety in the control group (Kain 2003).

Participants

The included trials investigated children aged up to 17 years and down to one month. Most trials excluded ASA III & IV (American Society of Anesthesiologists grading of anaesthesia risk as high) children and those with a history of chronic illness, preterm birth and developmental delay. Eight trials excluded children who had received previous surgery or anaesthesia or both (Arai 2007; Campbell 2005; Golan 2009; Kain 1996b; Meisel 2009; Vagnoli 2005; Vagnoli 2010; Zuwala 2001). Calipel 2005 excluded those who had been hospitalized six months prior to the study and Patel 2006 excluded children with repeated surgeries. Two studies excluded children with language barriers (Meisel 2009; Mifflin 2012). Berghmans 2012 and MacLaren 2008 did not report any exclusion criteria.

Most children received inhalational anaesthesia with oxygen, nitrous oxide and sevoflurane. Halothane was used in two studies (Kain 1996b; Kain 1998). Nine trials failed to describe the induction technique (Berghmans 2012; Bevan 1990; Fernandes 2010; Golan 2009; MacLaren 2008; McEwen 2007; Meisel 2009; Palermo 2000; Wright 2010).

Outcome assessments

Most studies used versions of the Yale Preoperative Anxiety Scale (YPAS, mYPAS) to assess anxiety of children. Other scales used were: hospital fear inventory; global mood scale; visual analogue scale (VAS); clinical anxiety rating scale; procedural behavioural rating scale; and the child behaviour scale. One study measured serum cortisol as a physiological indicator for anxiety (Kain 1996b). Co‐operation of children was reported in 11 trials. Eight trials (Berghmans 2012; Kain 1998; Kain 2000; Kain 2001; Kain 2004; Kain 2009; MacLaren 2008; Wang 2004) used the induction compliance checklist (ICC); two trials used coping VAS (Campbell 2005; Kain 1996b) and one trial measured child co‐operation by quality of mask induction (Arai 2007).

Parental anxiety was assessed using state trait anxiety inventory (STAI) in all but one of the 11 studies reporting this outcome. The other study reported parental anxiety using the Amsterdam Preoperative Anxiety and Information Scale (APAIS). Three studies (Kain 1996b; Kain 2003; Zuwala 2001) measured blood pressure, heart rate, and skin conductance as physiological indicators of parental anxiety.

Data on immediate postoperative behavioural changes in children were described in three studies employing two different scales: excitement scale (Kain 1996b; Kain 2000) and the emergence behaviour scale (Kain 2007). Others collected data on behavioural changes beyond day one from post‐hospital behavioural questionnaires. One study reported postoperative nausea and vomiting (PONV) in the postoperative unit (PACU), on days 1, 2 and 3 at home (Fortier 2010a). Parental satisfaction was measured by a 100 mm VAS (Kain 1996b) and Likert scales (Kain 1998; Palermo 2000).

Data on other outcomes of interest collected were: risk of adverse effects; time to discharge; analgesia requirements, nausea and vomiting; and health professionals' opinion regarding presence of clowns.

Excluded studies

The most common reasons for the 26 exclusions (16 new exclusions for this update) included method of induction not being inhalational and intervention applied prior to the day of surgery (see Characteristics of excluded studies).

Risk of bias in included studies

With no trial demonstrating low risk of bias allocation concealment combined with the inability to blind participants and personnel in most trials, we judged the overall risk of bias across the 28 included trials to be high (see Figure 2; Figure 3).

Risk of bias graph, authors' decision of each included study

(review plus update).

Risk of bias summary for each included study in both the review and update.

Allocation

Sequence generation

Most trials (n = 16) used low risk of bias methods of sequence generation, such as computer‐generated randomization; methods were unclear in nine trials and three trials were quasi‐randomized.

Allocation concealment

We could not classify any trial as having reported low risk of bias allocation concealment. In line with inadequate sequence generation, three trials also had high risk of bias allocation concealment. Of the remaining 25 trials, most (n = 17) did not report the method of allocation concealment.

Blinding

Blinding was often not possible because most interventions were visible to investigators and participants, and we judged only one trial to have low risk of bias blinding of investigators and participants (Wang 2004). Seven trials reported blinded assessment of outcomes.

Incomplete outcome data

Losses to follow‐up were generally small, as would be expected where most outcomes could be assessed soon after the intervention, with none of the 28 trials judged to be at high risk of bias for this component.

Selective reporting

We judged only one trial to be at high risk of reporting bias, as it reported only one outcome. However we rated many of the trials as unclear for this component.

Other potential sources of bias

We judged only one trial to be at high risk of other bias, due to a baseline imbalance in numbers randomized to each group.

Effects of interventions

See: Table 1; Table 2; Table 3

Summary of findings for the main comparison. Child intervention for assisting induction of anaesthesia for children.

Child intervention for assisting induction of anaesthesia for children
Patient or population: children  Settings: Belgium, France, Italy, Portugal, Spain, USA  Intervention: Child intervention for assisting induction of anaesthesia
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	Child intervention for assisting induction of anaesthesia
Co‐operation during induction ‐ Video 'fairytale' vs. no audiovisual aid (Passive)   ICC = 0 (perfect vs. poor‐moderate compliance)	383 per 1000	498 per 1000   (333 to 751)	RR 1.30   (0.87 to 1.96)	120  (1 study)	⊕⊝⊝⊝  very low^1,2
Co‐operation during induction ‐ Low sensory stimulation vs. control (Passive)   ICC = 0	784 per 1000	517 per 1000   (353 to 745)	RR 0.66   (0.45 to 0.95)	70  (1 study)	⊕⊝⊝⊝  very low^3,4
Co‐operation during induction ‐ Mask introduction/exposure (Mask)   ICC (number of children compliant)	737 per 1000	936 per 1000   (781 to 1000)	RR 1.27   (1.06 to 1.51)	102  (1 study)	⊕⊝⊝⊝  very low^3,5
Anxiety during induction ‐ Video game vs. midazolam (Interactive)   mYPAS. Scale from: 1 to 100.	The mean anxiety during induction ‐ video game vs. midazolam (interactive) in the control groups was  53.9 points	The mean anxiety during induction ‐ video game vs. midazolam (interactive) in the intervention groups was  12.2 lower   (21.82 to 2.58 lower)		76  (1 study)	⊕⊝⊝⊝  very low^6,7
Co‐operation during induction ‐ clowns/clown doctors vs. parental presence (Interactive)   SAM ‐ arousal. Scale from: 1 to 5.	The mean co‐operation during induction ‐ clowns/clown doctors vs. parental presence (interactive) in the control groups was  3.36 points	The mean co‐operation during induction ‐ clowns/clown doctors vs. parental presence (interactive) in the intervention groups was  1.70 lower   (2.33 to 1.07 lower)		70  (1 study)	⊕⊝⊝⊝  very low^8,9
Anxiety during induction ‐ hypnosis vs. midazolam (Interactive)   mYPAS < 24	667 per 1000	393 per 1000   (220 to 693)	RR 0.59   (0.33 to 1.04)	50  (1 study)	⊕⊝⊝⊝  very low^10,11
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; RR: Risk ratio;
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.

Parent intervention for assisting induction of anaesthesia for children
Patient or population: parents with children  Settings: USA  Intervention: Parent intervention for assisting induction of anaesthesia
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	Parent intervention for assisting induction of anaesthesia
Anxiety during induction ‐ Acupuncture for parents   mYPAS. Scale from: 1 to 100.	The mean anxiety during induction ‐ acupuncture for parents in the control groups was  55.6 points	The mean anxiety during induction ‐ acupuncture for parents in the intervention groups was  17 lower   (30.51 to 3.49 lower)		67  (1 study)	⊕⊕⊝⊝  low^1,2
Co‐operation during induction ‐ Acupuncture for parents   Perfect induction ICC=0	424 per 1000	675 per 1000   (428 to 1000)	RR 1.59   (1.01 to 2.53)	67  (1 study)	⊕⊕⊝⊝  low^1,2
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; RR: Risk ratio;
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.

Parental presence for assisting the induction of anaesthesia for children
Patient or population: children  Settings: Canada, Turkey, USA  Intervention: Parental presence for assisting the induction of anaesthesia
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	Parental presence for assisting the induction of anaesthesia
Anxiety during induction ‐ Parental presence vs. no parental presence		The standardized mean anxiety during induction ‐ parental presence vs. no parental presence in the intervention groups was  0.03higher   (0.14 lower to 0.20 higher)		557  (5 studies)	⊕⊝⊝⊝  very low^1,2	This equates to 0.78 mYPAS points higher (‐3.64 to 5.2).
Co‐operation during induction ‐ 2 parents vs. 1 parent   Poor compliance: ICC > 6	133 per 1000	251 per 1000   (81 to 763)	RR 1.88   (0.61 to 5.72)	58  (1 study)	⊕⊝⊝⊝  very low³^,4
Anxiety during induction ‐ Parental presence vs. midazolam   mYPAS. Scale from: 1 to 100.	The mean anxiety during induction ‐ parental presence vs. midazolam in the control groups was  40 points	The mean anxiety during induction ‐ parental presence vs. midazolam in the intervention groups was  10 higher   (2.91 to 17.09 higher)		192  (1 study)	⊕⊝⊝⊝  very low⁵^,6
Co‐operation during induction ‐ Parental presence vs. midazolam   Poor compliance: ICC > 6		⁷	RR 12.47   (0.72 to 216.2)	62  (1 study)	⊕⊝⊝⊝  very low⁸^,9
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; RR: Risk ratio;
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.

anxiety during induction
Study	PP (median, range)	No PP (median, range)	p value (n = 103)
VAS
Kain 1996b	VAS 45 (8 ‐ 86) YPAS 42 (30 ‐ 62) CARS 1 (0 ‐ 4)	43 (5 ‐ 78) 38 (24 ‐ 65) 1 (0 ‐ 4)	ns ns ns
mYPAS
Kain 2000	not reported	not reported	0.49
serum cortisol (mcg/ml)
Kain 1996b	76 (48 ‐ 91)	73 (51 ‐ 100)	ns

cooperation during induction
Study	PP + midazolam (median, range)	Midazolam (median, range)	P value
VAS
Kain 1996b	89, 73 ‐ 92 (n = 43)	85, 67 ‐ 91 (n = 41)	ns
ICC > 6 (poor)
Kain 2000	11% (overall n = 103; breakdown not reported)	15%	ns
Quality of mask induction (out of 3 ‐ 3 worst)
Arai 2007	2 (1 ‐ 3) (n = 19)	2 (1 ‐ 3) (n = 19)	ns

parental anxiety
Study	Parental presence + midazolam	Midazolam	P value
Kain 2000	mean 43 [SD 11]	mean 48 [SD 12]	P = 0.037 (controlling for parental anxiety at baseline)

emergence delirium
Study	PP (median)	PP (range)	no PP (median)	no PP (range)	p value
postoperative excitement score
Kain 1998	1 (n = 29)	1 ‐ 1.5	1 (n = 26)	1 ‐ 2	ns
Kain 2000	2 (n = 19)	1 ‐ 2	2 (n = 19)	1 ‐ 3	0.28
emergence behaviour (out of 5 ‐ 5 worst)
Arai 2007	3 (n = 19)	2 ‐ 4	4 (n = 19)	2 ‐ 5	0.05

parental satisfaction
Study	satisfaction with overall care	satisfaction with separation process
Kain 2000	P = 0.046 in favour of parental presence + midazolam	P = 0.03 in favour of parental presence + midazolam

anxiety at induction
Study	two parents (n = 28)	one parent (n = 30)	P‐value
mYPAS
Kain 2009	median, IQR 79.2 (37.5, 100)	median, IQR 41.7 (29.2, 90.1)	ns

anxiety during induction
Study	scale	PP	M	P value
entrance to OR
Kain 1998	mYPAS	n = 29	n = 33; lower anxiety	0.0171
introduction of mask
Kain 1998	mYPAS	n = 29	n = 33; lower anxiety	0.0176
Kazak 2010	anxiety scale	n = 20	n = 20; lower anxiety	< 0.05

cooperation during induction
Study	parental presence (median, range): n = 20	midazolam (median, range): n = 19	p value
quality of mask induction (out of 3; 3 worst)
Arai 2007	3 (2 ‐ 3)	2 (1 ‐ 3)	0.05

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 anxiety during induction	5	557	Std. Mean Difference (IV, Fixed, 95% CI)	0.03 [‐0.14, 0.20]
1.1 GMS total	1	130	Std. Mean Difference (IV, Fixed, 95% CI)	0.0 [‐0.34, 0.34]
1.2 Child behaviour scale	1	73	Std. Mean Difference (IV, Fixed, 95% CI)	0.40 [‐0.07, 0.86]
1.3 mYPAS	2	254	Std. Mean Difference (IV, Fixed, 95% CI)	‐0.05 [‐0.29, 0.20]
1.4 4 point scale (1 = agitated)	1	100	Std. Mean Difference (IV, Fixed, 95% CI)	0.0 [‐0.39, 0.39]
2 anxiety during induction			Other data	No numeric data
2.1 VAS			Other data	No numeric data
2.2 mYPAS			Other data	No numeric data
2.3 serum cortisol (mcg/ml)			Other data	No numeric data
3 anxiety during induction (parental anxiety subgroup)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
3.1 GMS anxious parent	1	49	Mean Difference (IV, Fixed, 95% CI)	1.1 [0.26, 1.94]
3.2 GMS calm parent	1	63	Mean Difference (IV, Fixed, 95% CI)	‐0.10 [‐0.94, 0.74]
4 cooperation during induction			Other data	No numeric data
4.1 VAS			Other data	No numeric data
4.2 ICC > 6 (poor)			Other data	No numeric data
4.3 Quality of mask induction (out of 3 ‐ 3 worst)			Other data	No numeric data
5 anxiety/distress before induction	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
5.1 separation from parent (mYPAS)	1	61	Mean Difference (IV, Fixed, 95% CI)	‐12.16 [‐19.90, ‐4.42]
6 parental anxiety (on day of surgery)	6		Mean Difference (IV, Random, 95% CI)	Subtotals only
6.1 VAS total	1	125	Mean Difference (IV, Random, 95% CI)	1.80 [‐10.43, 14.03]
6.2 STAI	1	73	Mean Difference (IV, Random, 95% CI)	2.0 [‐0.30, 4.30]
6.3 STAI (trait)	1	100	Mean Difference (IV, Random, 95% CI)	1.0 [‐2.34, 4.34]
6.4 STAI (state)	3	239	Mean Difference (IV, Random, 95% CI)	‐1.74 [‐4.55, 1.07]
6.5 systolic blood pressure (mmHg)	2	137	Mean Difference (IV, Random, 95% CI)	‐1.39 [‐6.18, 3.40]
6.6 diastolic blood pressure (mmHg)	2	137	Mean Difference (IV, Random, 95% CI)	‐1.51 [‐4.68, 1.65]
6.7 heart rate	1	84	Mean Difference (IV, Random, 95% CI)	‐1.0 [‐4.88, 2.88]
7 parental anxiety (physiological signs)	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
7.1 isolated ventricular ectopy	1	53	Risk Ratio (M‐H, Fixed, 95% CI)	0.83 [0.18, 3.73]
7.2 single premature atrial contractions	1	53	Risk Ratio (M‐H, Fixed, 95% CI)	0.55 [0.10, 3.04]
8 parental anxiety during induction (parental anxiety subgroup)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
8.1 VAS anxious parent	1	49	Mean Difference (IV, Fixed, 95% CI)	16.10 [2.39, 29.81]
8.2 VAS calm parent	1	63	Mean Difference (IV, Fixed, 95% CI)	‐10.90 [‐27.84, 6.04]
9 parental anxiety postop	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
9.1 PQ 1 week postop	1	121	Mean Difference (IV, Fixed, 95% CI)	0.20 [0.02, 0.38]
10 parental anxiety			Other data	No numeric data
11 emergence delirium	1	193	Risk Ratio (M‐H, Fixed, 95% CI)	0.66 [0.37, 1.18]
12 emergence delirium			Other data	No numeric data
12.1 postoperative excitement score			Other data	No numeric data
12.2 emergence behaviour (out of 5 ‐ 5 worst)			Other data	No numeric data
13 time taken for induction (minutes)	2	139	Mean Difference (IV, Random, 95% CI)	‐0.94 [‐2.41, 0.53]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 anxiety at induction			Other data	No numeric data
1.1 mYPAS			Other data	No numeric data
2 co‐operation during induction	1	58	Risk Ratio (M‐H, Random, 95% CI)	1.88 [0.61, 5.72]
2.1 poor compliance: ICC > 6	1	58	Risk Ratio (M‐H, Random, 95% CI)	1.88 [0.61, 5.72]
3 parental anxiety after leaving OR	1	58	Mean Difference (IV, Fixed, 95% CI)	‐8.90 [‐15.23, ‐2.57]
3.1 STAI	1	58	Mean Difference (IV, Fixed, 95% CI)	‐8.90 [‐15.23, ‐2.57]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 anxiety during induction	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
1.1 mYPAS	1	192	Mean Difference (IV, Fixed, 95% CI)	10.0 [2.91, 17.09]
2 anxiety during induction			Other data	No numeric data
2.1 entrance to OR			Other data	No numeric data
2.2 introduction of mask			Other data	No numeric data
3 cooperation during induction	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
3.1 poor compliance; ICC > 6	1	62	Risk Ratio (M‐H, Fixed, 95% CI)	12.47 [0.72, 216.20]
4 cooperation during induction			Other data	No numeric data
4.1 quality of mask induction (out of 3; 3 worst)			Other data	No numeric data
5 parental anxiety	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
5.1 STAI	1	62	Mean Difference (IV, Fixed, 95% CI)	4.0 [‐1.48, 9.48]
6 time taken for induction (minutes)	1	62	Mean Difference (IV, Fixed, 95% CI)	0.60 [0.36, 0.84]
7 emergence delirium	1	192	Risk Ratio (M‐H, Fixed, 95% CI)	0.74 [0.41, 1.36]
8 emergence delirium			Other data	No numeric data
8.1 postoperative excitement score			Other data	No numeric data
8.2 emergence behaviour (out of 5; 5 worst)			Other data	No numeric data
9 negative behaviour postop	1	62	Risk Ratio (M‐H, Fixed, 95% CI)	0.91 [0.51, 1.61]
9.1 2 weeks postop	1	62	Risk Ratio (M‐H, Fixed, 95% CI)	0.91 [0.51, 1.61]
10 parental satisfaction	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
10.1 overall	1	62	Risk Ratio (M‐H, Fixed, 95% CI)	0.96 [0.88, 1.06]
10.2 anaesthetists	1	62	Risk Ratio (M‐H, Fixed, 95% CI)	0.90 [0.78, 1.03]
10.3 nursing staff	1	62	Risk Ratio (M‐H, Fixed, 95% CI)	1.0 [0.94, 1.06]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 parental anxiety	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
1.1 systolic blood pressure (mmHg)	1	51	Mean Difference (IV, Fixed, 95% CI)	2.0 [‐7.71, 11.71]
1.2 diastolic blood pressure (mmHg)	1	51	Mean Difference (IV, Fixed, 95% CI)	4.0 [‐3.75, 11.75]
2 parental anxiety	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
2.1 isolated ventricular ectopy	1	51	Risk Ratio (M‐H, Fixed, 95% CI)	0.89 [0.20, 4.00]
2.2 single premature atrial contractions	1	51	Risk Ratio (M‐H, Fixed, 95% CI)	0.59 [0.11, 3.25]

emergence delirium
Study	PP (mean, range) n = 20	M (mean, range) n = 19	P
postoperative excitement score
Kain 1998	1 (1 ‐ 1.5)	1 (1 ‐ 2)	ns
emergence behaviour (out of 5; 5 worst)
Arai 2007	4 (2 ‐ 5)	4 (2 ‐ 5)	ns

co‐operation during induction
Study	PP (VAS ‐ median, range)	PP (n)	PP+computer (VAS ‐ median, range)	PP+computer (n)	p value
coping VAS
Campbell 2005	3 (0 ‐ 10)	58	1 (0 ‐ 10)	55	0.014

Date	Event	Description
7 July 2015	New search has been performed	We added 11 new trials (Akinci 2008; Berghmans 2012; Fernandes 2010; Golan 2009; Kain 2009; Kazak 2010; MacLaren 2008; Meisel 2009; Mifflin 2012; Vagnoli 2010; Wright 2010).
7 July 2015	New citation required but conclusions have not changed	The main objective of this review was to update the previous Cochrane systematic review known as 'Non‐pharmacological interventions for assisting the induction of anaesthesia in children' (Yip 2009) that concluded that some interventions (parental acupuncture, clown doctors, hypnosis, low sensory stimulation and hand‐held video games) were likely to be helpful in reducing children's anxiety and improving their co‐operation during induction of general anaesthesia. The original review included 17 randomized controlled trials (RCTs). In updating the review, two new authors (CC and MA) joined the original team (PY, PM, AVC and AMC). AVC is no longer an author or involved in this review. We found 25 new trials and included 11 of them since they met our inclusion criteria (RCT of a non‐pharmacological intervention implemented on the day of surgery or anaesthesia). Fourteen RCTs were excluded either because inappropriate induction methods (n = 5) or interventions (n = 8) were used. We also excluded one which was not randomized and three studies involving adults. In general our review reached the same conclusions as Yip 2009. However, we included more trials and thus now have more precise estimates on some risk ratios. Furthermore, we applied several additional sensitivity and subgroup analyses which supported the overall results. We have also extended our search strategy to include additional electronic databases. In the previous version, the databases were searched until December 2008. We reran the searches until 28 August 2014. We have included a study flow diagram which documents the selection process of the trials included in the update review (Figure 1), a risk of bias graph with authors' decision of each included study (Figure 2) and risk of bias summary of each included study (Figure 3). We added one study to 'Studies awaiting classification'.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 co‐operation	1	120	Risk Ratio (M‐H, Fixed, 95% CI)	1.30 [0.87, 1.96]
1.1 ICC = 0 (perfect vs poor‐moderate compliance)	1	120	Risk Ratio (M‐H, Fixed, 95% CI)	1.30 [0.87, 1.96]
2 parental anxiety (STAI ≥ 46)	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
2.1 in holding bay	1	120	Risk Ratio (M‐H, Fixed, 95% CI)	0.55 [0.30, 1.00]
2.2 after leaving operating theatre	1	120	Risk Ratio (M‐H, Fixed, 95% CI)	1.0 [0.70, 1.43]
3 parental anxiety (APAIS ≥ 13)	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
3.1 in holding bay	1	120	Risk Ratio (M‐H, Fixed, 95% CI)	0.52 [0.28, 0.99]
3.2 after leaving operating theatre	1	120	Risk Ratio (M‐H, Fixed, 95% CI)	0.46 [0.26, 0.83]
4 parental anxiety (STAI)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
4.1 STATE: in holding area	1	120	Mean Difference (IV, Fixed, 95% CI)	‐5.30 [‐9.04, ‐1.56]
4.2 STATE: after leaving operating theatre	1	120	Mean Difference (IV, Fixed, 95% CI)	‐5.0 [‐9.51, ‐0.49]
5 parental anxiety (APAIS)	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
5.1 STATE: in holding area	1	120	Mean Difference (IV, Fixed, 95% CI)	‐1.70 [‐3.02, ‐0.38]
5.2 STATE: after leaving operating theatre	1	120	Mean Difference (IV, Fixed, 95% CI)	‐2.0 [‐3.39, ‐0.61]
5.3 INFORMATION: in holding area	1	120	Mean Difference (IV, Fixed, 95% CI)	0.10 [‐0.53, 0.73]
5.4 INFORMATION: after leaving operating theatre	1	120	Mean Difference (IV, Fixed, 95% CI)	0.0 [‐0.76, 0.76]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 co‐operation at induction	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
1.1 ICC = 0	1	70	Risk Ratio (M‐H, Fixed, 95% CI)	0.66 [0.45, 0.95]
2 parental anxiety	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
2.1 STAI	1	70	Mean Difference (IV, Fixed, 95% CI)	‐2.0 [‐9.03, 5.03]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 anxiety	1		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
1.1 post intervention (introduction of mask)	1	103	Risk Ratio (M‐H, Fixed, 95% CI)	6.44 [0.78, 53.23]
1.2 at induction of anaesthesia	1	103	Risk Ratio (M‐H, Fixed, 95% CI)	0.59 [0.31, 1.11]
2 co‐operation (ICC): number of children compliant	1	102	Risk Ratio (M‐H, Fixed, 95% CI)	1.27 [1.06, 1.51]
3 parental anxiety (STAI: trait)	1	102	Mean Difference (IV, Fixed, 95% CI)	‐1.06 [‐3.35, 1.23]

Outcome or subgroup title	Statistical method	Effect size
1 co‐operation during induction	Other data	No numeric data
1.1 coping VAS	Other data	No numeric data
2 negative behavioural changes	Other data	No numeric data
2.1 coping VAS	Other data	No numeric data

Methods	RCT
Participants	100 children ages of 2 ‐ 10, ASA I ‐ II, elective ambulatory surgery under general anaesthesia Exclusions: children with a past history of cardiac, pulmonary, hepatic or renal insufficiency or who had known psychological problems. Setting: Turkey
Interventions	PARENTAL PRESENCE: Parental presence (mother present): n = 50 No parental presence (mother absent): n = 50 All had midazolam 0.5 mg/kg intranasally at least 20 minutes before surgery All received inhalation induction: oxygen/nitrous oxide/sevoflurane
Outcomes	Preoperatively (on day of surgery): child's behaviour measured by PHBQ At induction: child's level of stress using 4‐point scale (1 = agitated, crying and not co‐operative, 4 = sleeping) Preoperatively (on the day of surgery) mother's trait anxiety measured by STAI (Trait) Preoperatively (on day of surgery): mother's state anxiety measured by STAI (State) Postoperatively (1 week after surgery): mother's state anxiety measured by STAI (State)
Notes	The mother completed the PHBQ preoperatively to determine the child's behaviour disturbances A psychologist assessed and administered the STAI and PHBQ postoperatively
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number table
Allocation concealment (selection bias)	Unclear risk	Methods of allocation concealment not reported
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Not reported but blinding unlikely due to the nature of the interventions
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	"A psychologist functioned as the assessor"
Incomplete outcome data (attrition bias)   All outcomes	Low risk	No losses reported
Selective reporting (reporting bias)	Unclear risk	Limited number of outcomes reported
Other bias	Low risk	No other concerns noted

Methods	RCT
Participants	60 children Inclusion criteria: Children aged 1 ‐ 3 years, ASA I undergoing minor plastic surgery under GA Exclusion: History of chronic illness, prematurity or developmental delay, history of previous surgery Setting: university hospital, Japan
Interventions	PARENTAL PRESENCE Parental presence (mother) ‐ mother held child throughout induction of anaesthesia (n = 20) Parental presence (mother) + midazolam (both as above and below); n = 19 Sedative (midazolam 0.5 mg/kg oral 40 minutes before induction) n = 19 All participants: Anaesthesia: induced with 7% sevoflurane in 100% oxygen, maintained with sevoflurane 1.5 ‐ 2.5 in 60% oxygen and intravenous fentanyl 4 mcg/kg Sevoflurane was discontinued at the end of surgery
Outcomes	Emergence behaviour: 5‐point scale: Obtunded with no response to stimuli Asleep but response to movement or stimulation Awake and responsive Inconsolable crying Thrashing behaviour requiring restraint Quality of mask induction (entered as Co‐operation in this review): 3‐point scale: Readily accepts mask Minimally resistant Fighting
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random numbers
Allocation concealment (selection bias)	Unclear risk	Methods of allocation concealment not reported
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Not reported, but unlikely due to the nature of the intervention
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	Outcome assessment was blinded
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	2 children refused the whole midazolam dose (1 in the midazolam‐only group and 1 in the midazolam + parental presence group)
Selective reporting (reporting bias)	Unclear risk	Child anxiety not reported; no parental outcomes reported
Other bias	Unclear risk	No apparent sources of other bias

Methods	RCT
Participants	120 children and their parents (mostly mothers), ages 6 months ‐ 16 years, ASA I or II, scheduled for day‐care surgery (most frequent procedures were urology (32%) in the control group and ears, nose, throat (ENT) (35%) in the intervention group) No premedication was administered Setting: Belgium
Interventions	CHILD/PARENT INTERVENTION (PASSIVE): Audiovisual aid (video 'fairytale'): n = 60; parents (and children) watched the video before induction in holding area. No audiovisual aid used: n = 60 Method of induction: not stated.
Outcomes	Child's anxiety score at induction measured with a VAS (marked 'not anxious at all' and 'very anxious') presented as median and 95% CI Co‐operation measured with ICC ( perfect induction: ICC = 0; moderate compliance: ICC = 1 ‐ 3; poor compliance: ICC > 4) by the parent and by the anaesthetist Parental anxiety was measured by the STAI (state and trait) and the APAIS ‐ state and APAIS ‐ information, presented as mean and 95% CI; and also as numbers of anxious parents (STAI ≥ 46; APAIS ≥ 13). Parental anxiety was measured at 3 time points ‐ on admission, in the holding area, and after leaving the operating theatre; only the latter 2 were included as parents had not yet been exposed to the intervention (watching the video) at admission
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random sequence
Allocation concealment (selection bias)	Unclear risk	Parents picked a computer‐generated randomly numbered envelope
Blinding of participants and personnel (performance bias)   All outcomes	Unclear risk	Not feasible to blind participants and personnel
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	Child anxiety was assessed by anaesthetists blinded to group allocation
Incomplete outcome data (attrition bias)   All outcomes	Low risk	No losses reported
Selective reporting (reporting bias)	Unclear risk	Most expected outcomes are reported, although child anxiety is reported as median and 95% CI
Other bias	Low risk	No other concerns apparent

PERMALINK

Non‐pharmacological interventions for assisting the induction of anaesthesia in children

Anne Manyande

Allan M Cyna

Peggy Yip

Cheryl Chooi

Philippa Middleton

Abstract

Background

Objectives

Search methods

Selection criteria

Data collection and analysis

Main results

Authors' conclusions

Plain language summary

Summary of findings

Background

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

Outcome Measures

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

Assessment of heterogeneity

Assessment of reporting biases

Data synthesis

Subgroup analysis and investigation of heterogeneity

Sensitivity analysis

Results

Description of studies

Results of the search

1.

Included studies

Excluded studies

Risk of bias in included studies

2.

3.

Allocation

Sequence generation

Allocation concealment

Blinding

Incomplete outcome data

Selective reporting

Other potential sources of bias

Effects of interventions

Summary of findings for the main comparison. Child intervention for assisting induction of anaesthesia for children.

Summary of findings 2. Parent intervention for assisting induction of anaesthesia for children.

Summary of findings 3. Parental presence for assisting the induction of anaesthesia for children.

1. Parental presence

1.1 Parental presence versus no parental presence

Primary outcomes

1.1. Analysis.

1.2. Analysis.

1.3. Analysis.

1.4. Analysis.

Secondary outcomes

1.5. Analysis.

1.6. Analysis.

1.7. Analysis.

1.8. Analysis.

1.9. Analysis.

1.10. Analysis.

1.11. Analysis.

1.12. Analysis.

1.13. Analysis.

1.14. Analysis.

1.15. Analysis.

Methods	Quasi‐RCT
Participants	134 children ages 2 ‐ 10 years, ASA I ‐ II, who spoke French or English and accompanied by parents with whom they usually lived All types of surgery included Setting: Canada; Day Surgery Centre of Montreal Children's Hospital
Interventions	PARENTAL PRESENCE Parental presence (n = 65) No parental presence (n = 65) Method of induction: not stated
Outcomes	Child behaviour responses as measured by 'Hospital fears inventory' (1 = no fear, 5 = very much) preoperatively and after discharge; Global mood scale (1 = playing happily, 7 = screaming) at induction; and behavioural questionnaire 1 week postoperatively (mean for each question). 100 mm VAS to measure anxiety of children at induction. Parental anxiety was measured using questionnaire and 100 mm VAS
Notes	Parents were divided into 'anxious' or 'calm' based on a median split of their anxiety scores (median VAS 42) in the waiting room
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Allocation was by day of the week
Allocation concealment (selection bias)	High risk	Allocation was by day of the week
Blinding of participants and personnel (performance bias)   All outcomes	Unclear risk	States parents and child were blinded, although this not likely
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	Nurse observers could not be blinded.
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	2 children allocated had parental presence despite allocation to control and excluded from analysis. Variable dropouts of between 1 and 7 participants with responses to the different measures.
Selective reporting (reporting bias)	Low risk	Most expected outcomes were reported
Other bias	Unclear risk	No explanation why only 112 of the 130 parents were classified as anxious or calm

Methods	RCT
Participants	50 children ages 2 ‐ 11. ASA I ‐ II, ambulatory, lower abdominal surgery Exclusions: Hospitalization in last 6 months; emergency surgery; psychological retardation Setting: France
Interventions	CHILD/PARENT INTERVENTION: HYPNOSIS Hypnosis: n = 23 (participants allocated to hypnosis received placebo premed plus hypnotic interaction with anaesthetist for 30 minutes prior to induction) Midazolam: n = 27 (midazolam participants received midazolam 0.5 mg/kg 30 minutes before surgery and nurse to take patient to theatre). Inhalational induction with oxygen/nitrous oxide/sevoflurane
Outcomes	mYPAS (0 ‐100 scale, higher score = greater anxiety) on arrival; entrance to operating room; and on applying facemask; mYPAS > 24 classified as anxious Hospitalization behavioural questionnaire measured Day 1 and 7 postoperatively Postoperative pain in recovery measured by objective pain score at 1, 30, 60, 120 minutes
Notes	Some children had parental presence which was not controlled for
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Two randomized groups"
Allocation concealment (selection bias)	Unclear risk	"Two randomized groups"; no further details reported
Blinding of participants and personnel (performance bias)   All outcomes	Unclear risk	Parent and participant blinded but probably partially at best as children in the hypnosis group talked with the anaesthetist while s/he established a "hypnotic relation"; not clear if nurse observer blinded
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias)   All outcomes	Low risk	No losses reported
Selective reporting (reporting bias)	Unclear risk	Not all expected outcomes were reported or reported fully
Other bias	Low risk	No apparent sources of other bias

Methods	RCT
Participants	198 children aged 3 ‐ 10, for dental extractions under general anaesthesia. No previous experience of either medical or dental general anaesthesia. English as first language Setting: dental general anaesthesia service, Scotland
Interventions	CHILD/PARENT INTERVENTION: COMPUTER/CARTOON Interactive computer package preparation (n = 55) Paper‐based cartoon preparation (n = 55) Control (verbal preparation) (n = 58) Majority of children had inhalational sevoflurane induction. If specifically requested, an intravenous induction was used. All had parental presence
Outcomes	Coping VAS (0 ‐ 10) at induction and recovery (measuring co‐operation and negative behaviour); all reported as medians and ranges
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computerized randomization grid
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment not reported
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Not feasible to blind the intervention
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	Outcome assessors were blinded
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	30/198 (15%) children not assessed for coping behaviour at induction and 32/198 not assessed at recovery (losses by group not reported)
Selective reporting (reporting bias)	Unclear risk	No parental outcomes reported
Other bias	Low risk	No other risk of bias apparent

Methods	QuasiRCT
Participants	70 children (53 boys) aged 5 ‐ 12, scheduled for minor surgery (such as circumcision, herniorrhaphy, excision, orchiopexy and cystoscopy) Inclusion criteria: undergoing minor surgery, accompanied by a family member(mother or father or both), between 5 and 12 years of age and having parental consent to participate Exclusions: children under the age of 5, a history of neurological or psychopathology disorder as reported by their parents Setting: Portugal
Interventions	CLOWNS/CLOWN DOCTORS Clowns and parents group (n = 35): a pair of clowns (male and female) and parents arrived with the child in the ambulatory room 30 minutes before surgery; the clowns entertained the child for 15 minutes with magic tricks, music, jokes, games and humour Parents‐only group: n = 35 All participants: Method of induction not stated
Outcomes	Child's temperament: was assessed by their parents through completion of the EAS Temperament Survey for Children Child's preoperative worries about surgery: was assessed using the CSWQ; 23 items, 5‐point scale Emotional responses: The SAM scale was used to measure the dimensions of valence and arousal Parents' preoperative state of anxiety: STAI Health professionals' opinion regarding presence of clowns: The questionnaire to ascertain the effectiveness of clowns was based on Vagnoli 2005
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	By day of week
Allocation concealment (selection bias)	High risk	The 2 groups were scheduled for different days in order to avoid the awareness of the comparison group about the presence of clowns with children in the treatment group
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Not possible to blind this intervention
Blinding of outcome assessment (detection bias)   All outcomes	High risk	Assessors were not blind to the presence or absence of the clowns
Incomplete outcome data (attrition bias)   All outcomes	Low risk	No losses reported
Selective reporting (reporting bias)	Low risk	Most expected outcomes were reported
Other bias	Low risk	No other concerns

Methods	RCT
Participants	65 children aged 3 ‐ 8 years, ASA I ‐ II scheduled to undergo general anaesthesia and elective outpatient surgery Exclusions: a history of previous anaesthesia or chronic illness, preterm birth, developmental delay, or significant hearing or visual impairments Setting: USA
Interventions	CHILD/PARENT INTERVENTIONS: CLOWN DOCTORS/CLOWNS Clowns (n = 21): children had two specially trained female clowns present upon arrival to the preoperative holding area and throughout OR entrance and mask application for inhalation induction of anaesthesia Midazolam (n = 22): children received 0.5 mg/kg oral midazolam 30 minutes before surgery up to a maximum of 15 mg Control (n = 22): children did not receive midazolam or clown presence All participants: Method of induction not stated; parents present
Outcomes	Preoperative child anxiety at the entrance to operating room (OR): mYPAS Preoperative child anxiety during application of mask: mYPAS
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random assignment
Allocation concealment (selection bias)	Unclear risk	No details of method of allocation concealment reported
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Not feasible to blind the intervention
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	Evaluators were blinded (although clowns may have been visible in some videos)
Incomplete outcome data (attrition bias)   All outcomes	Low risk	No losses reported
Selective reporting (reporting bias)	Unclear risk	Only 1 outcome reported (child anxiety)
Other bias	Low risk	No other risk of bias apparent

Methods	RCT
Participants	84 children ages 1 ‐ 6, ASA I ‐ II, elective outpatient surgery under general anaesthesia Exclusion: previous surgery, hospitalization, chronic illness, developmental delay Setting: Children's Hospital at Yale‐New Haven, USA
Interventions	PARENTAL PRESENCE Parental presence (n = 43) No parental presence (n = 41) All inductions were in the morning with parents dressed in own clothing, using oxygen/nitrous oxide/halothane in induction room
Outcomes	At induction: child anxiety (YPAS, CARS : 0 = relaxed, 5 = loud cry and out of contact with reality) and co‐operation (VAS), serum cortisol sampled immediately after intravenous cannula insertion Parental anxiety was measured by STAI, blood pressure, heart rate. Anaesthetist's blood pressure, heart rate and rated own situational anxiety (STAI 20 ‐ 80 with higher scores denoting higher levels of anxiety) and completed questionnaire rating helpfulness of parents Duration of induction time Nausea and vomiting and other anaesthetic complications Time to discharge Parents rated own helpfulness to their child and satisfaction with medical staff using 100 mm VAS Post‐hospital behavioural questionnaire completed by parents at 2 weeks and 6 months
Notes	All participated in a behavioural preoperative preparation programme (consists of providing information to the child and parent, an orientation tour of the operating room and post‐anaesthesia care unit and modelling using dolls by child‐life specialists related to the specific surgery planned for the child)
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated numbers table
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment not reported
Blinding of participants and personnel (performance bias)   All outcomes	Unclear risk	Observers and patients could not be blinded because of the nature of intervention.
Blinding of outcome assessment (detection bias)   All outcomes	Low risk	Anxiety of both children and parents was rated by independent "blinded" observers using VAS preoperatively; all inductions were videotaped and analysed
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	6 failed to complete post‐hospital behavioural questionnaire at 2 weeks. 22 failed to complete questionnaire at 6 months
Selective reporting (reporting bias)	Low risk	Comprehensive range of outcomes reported
Other bias	Low risk	No apparent evidence of other sources of bias

Methods	RCT
Participants	93 children ages 2 ‐ 8, ASA I ‐ II, elective outpatient surgery under general anaesthesia Exclusion: history of chronic illness, prematurity, developmental delay, parents who insisted on a particular study group Setting: USA
Interventions	PARENTAL PRESENCE Parental presence (n = 29) Midazolam (0.5 mg/kg orally mixed with 10 mg/kg acetaminophen syrup at least 30 minutes before procedure) (n = 33) Control ‐ no parental presence; no medication (n = 26) All had inhalational gaseous induction with oxygen/nitrous oxide/halothane
Outcomes	Child anxiety measured by YPAS and PBRS: 0 = behaviour did not occur, 3 = behaviour was extreme or lasted a specific amount of time) Co‐operation of children at induction was rated using ICC (1= compliant, > 1 = non‐compliant) Parental anxiety measured by STAI Post‐hospital behavioural questionnaire at 2 weeks post‐operative (incidence of negative behaviour) Excitement scale was used to rate postoperative excitement Parental satisfaction with nursing, anaesthesia, overall medical care and overall function of the surgical centre was measured by Likert scale (poor = 0, very good = 4) Adverse effects, analgesic requirements, pain scores (Children's Hospital of Eastern Ontario Pain Scale), time to first void, amount of fluid intake Time to discharge from the PACU and time to 'postoperative recovery' (assessed by SPRS)
Notes	48 children participated in behavioural preoperative preparation program
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Random number table
Allocation concealment (selection bias)	Unclear risk	"Managing anaesthesiologist, parents, and assessor did not know the randomization code"
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Not feasible to blind this intervention
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	Assessors were blinded in the midazolam vs control group but not to the parental‐presence group; research nurse who carried out phone interviews to complete post‐hospitalization behaviour questionnaire was blinded
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	No losses to follow‐up but 5 children were excluded post‐randomization because of violation of anaesthetic protocol (sevoflurane instead of halothane); not reported which groups these exclusions were from
Selective reporting (reporting bias)	Low risk	Most expected outcomes were reported
Other bias	Unclear risk	No apparent evidence of other sources of bias

Methods	RCT
Participants	103 children ages 2 ‐ 8, ASA I ‐ II, outpatient surgery under general anaesthesia Exclusions: history of chronic illness, prematurity, developmental delay Setting: USA
Interventions	PARENTAL PRESENCE Parental presence and oral midazolam (0.5 mg/kg): n not clear Oral midazolam (0.5 mg/kg) without parental presence: n not clear All received inhalational induction with oxygen/nitrous oxide/sevoflurane
Outcomes	Child anxiety measured by mYPAS. ICC was used to assess co‐operation of children at induction Parental anxiety was measured using STAI Satisfaction questionnaire completed by parents 2 weeks postoperatively Postoperative excitement scale was used to measure behavioural changes in recovery Anaesthetic complications were recorded
Notes	Some participated in preoperative preparation programme voluntarily Insufficient reporting (e.g. numbers of children in each group not reported) limited the ability to meta‐analyse the results from this trial
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random numbers table
Allocation concealment (selection bias)	Unclear risk	Yoked design based on surgical histories; the 1st child undergoing surgery who had not undergone surgery before was randomized to 1 of the 2 groups. The 2nd child undergoing surgery with no surgical history was allocated automatically to the other group. This ensured almost equal distribution of surgical experience in the 2 groups
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Not reported but unlikely due to the nature of the intervention
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	8 losses to follow‐up (groups not reported): 5 children were excluded due to protocol violations (e.g. refusal to swallow the sedative premedication); 3 families refused to participate "after notification that they had been randomized to undergo the operation"; 68% response rate to the parent satisfaction questionnaire.
Selective reporting (reporting bias)	Low risk	Most expected outcomes were reported
Other bias	Low risk	No apparent evidence of other sources of bias (apart from some incomplete reporting as mentioned above)

Methods	RCT
Participants	70 children, ages 2 ‐ 7, ASA I ‐ II Exclusions: any history of chronic illness, prematurity, or developmental delay Setting: USA
Interventions	CHILD/PARENT INTERVENTION: LOW SENSORY STIMULATION Low sensory stimulation group (LSSG) ‐ low light, background music (lights dimmed at 200LX, Bach's 'Air on a G string' was played using a CD player set at the 50‐60 dB located at a set distance from the child): n = 33 Control: n = 37 All received inhalational induction: oxygen/nitrous oxide/sevoflurane
Outcomes	mYPAS was used to rate anxiety of children Induction co‐operation was measured using the ICC Parental anxiety was measured by STAI Post‐hospitalization behavioural questionnaire was completed by parents at day 1, 2, 3, 7 & 14 postoperatively Other outcomes: adverse effects, time to discharge, analgesia requirement
Notes	Parental presence was used as rescue therapy on separation to the theatre 11 times (5 in the LSSG and 6 control group)
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated list created from a random‐number table
Allocation concealment (selection bias)	Unclear risk	"Randomized" ‐ yoked design based on child's age type of surgery, and participation in the preoperative preparation programme
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Not reported but unlikely due to the nature of the intervention
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias)   All outcomes	Low risk	No losses reported
Selective reporting (reporting bias)	Unclear risk	Most expected outcomes were reported although actual numerical results were not always reported
Other bias	Unclear risk	No apparent evidence of other sources of bias

Methods	RCT
Participants	80 children, ASA I ‐ II, elective outpatient surgery Children had a mean age of about 5 years Exclusion: history of chronic illness, prematurity, developmental delay Setting: USA
Interventions	PARENTAL PRESENCE Parental presence (n = 29) Parental presence and oral midazolam 0.5 mg/kg 30 minutes prior (n = 27) Control (n = 24) All had inhalational induction using oxygen/nitrous oxide/sevoflurane
Outcomes	mYPAS was used to rate anxiety of children Parental anxiety was measured by STAI, changes in heart rate, skin conductance and blood pressure
Notes	Some participated in behavioural preoperative preparation programmes voluntarily
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Based on a random number table, parents were assigned to one of the following three experimental groups..."
Allocation concealment (selection bias)	Unclear risk	See above
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Not feasible to blind participants and personnel
Blinding of outcome assessment (detection bias)   All outcomes	Unclear risk	Not reported, but objective data from Biolog were used to measure physiological variables
Incomplete outcome data (attrition bias)   All outcomes	Low risk	No losses reported
Selective reporting (reporting bias)	Unclear risk	Only anxiety (child and parent) reported, with child anxiety reported only as no significant difference between groups
Other bias	Low risk	Parental presence was used a rescue in 1 child in the control group; no apparent source of other bias