1. Non‐Cochrane reviews: characteristics of excluded reviews.

Name of Review	Description of review	Reason for exclusion
Arnal 2009	This paper examined IV remifentanil for pain relief in labour. (The paper is in Spanish and eligibility assessment was carried out using the abstract only).	This review examines IV remifentanil and this topic is covered in a recently updated Cochrane review.
Aveline 2001	This review examined epidural and combined spinal epidural. The main focus of the review is on the duration of labour and the mode of delivery. It appeared that only five studies were included, although others were discussed in the text. There did not appear to have been any systematic assessment of bias. (This paper was published in French, so this assessment mainly relied on details in the abstract).	The topic of this review is covered in a recently updated Cochrane review.
Benfield 2002	This review focused on hydrotherapy for pain relief in labour.There was no description of the methods used to carry out this review. There was no systematic search strategy or method of data extraction, no clear inclusion and exclusion criteria. There was no systematic assessment of risk of bias. All types of studies were included. There was no meta analysis, rather a narrative description of findings.	This was not a systematic review.
Bricker 2002	This systematic review examined parenteral opioids. Cochrane methods were used and analysis was carried out using Review Manager software.	This systematic review of parenteral opioids, has been superseded by a recently updated Cochrane systematic review.
Bucklin 2002	The review appeared to have been carried out in a systematic manner. The search criteria, comparisons, inclusion and exclusion criteria were stated along with outcomes. It was not clear that there was a systematic quality assessment of studies. One measure of quality was stated to be publication in a peer reviewed journal. There was no mention of domain based quality assessment but in the tables in the review there were notes re study design that included risk of bias e.g.. It was stated if the study was blinded and whether staff collecting outcome data were blinded.	The topic of this review is covered in an included systematic review.
Capogna 2004	This review was a mainly narrative summary of findings from RCTs and other reviews (with meta‐analysis) focusing on various types of epidural and CSE. It examined different doses and types of drugs and comparisons. The main focus was on neonatal outcome. The methods of the review were not described. There was no search strategy specified, no clear inclusion and exclusion criteria, and no systematic assessment of quality.	Not a systematic review.
Carroll 1997	This review examines TENS in labour. The review methods were described. The search strategy and inclusion and exclusion criteria were specified. Outcomes included analgesic effect and adverse effects. There was systematic assessment of study quality including blinding and attrition. The review included 8 RCTs. The review was carried published in 1997 and the more recent Cochrane TENS review examined all of the eight included trials along with other more recent RCTs.	A more recent Cochrane review examines TENS for pain relief in labour.
Carroll 1997a	This is an update of Carroll 1997 and includes 10 RCTs.	A more recent Cochrane review examines TENS for pain relief in labour.
Cho 2010	This review focusing on acupuncture for pain relief in labour uses Cochrane methods and Review Manager software was used to carry out meta‐analysis.	This review covers the same topic as a Cochrane review.
Choi 2003	This review was not examining pain management in labour, rather it focused on the incidence of headache following epidural.	The topic of this review is covered in a recently updated Cochrane review.
Cyna 2004a	There has been a more recent Cochrane review on the same subject by the same author.	The topic of this review is covered in a recently updated Cochrane review.
Fogarty 2008	This review on intradermal sterile water injections for the relief of low back pain in labour provides a narrative summary of findings from reviews. There is no meta‐analysis and there has been a more recent Cochrane review on the same topic.	The topic of this review is covered in a recently updated Cochrane review.
Habib 2006	This review mainly focused on patients undergoing surgery rather than women in labour.	The primary focus of this review was not on women in labour.
Hager 1999	This is a critique of an earlier review.	This is not a systematic review.
Halpern 1998	This is a systematic review of the effects of epidural versus parenteral opioid analgesia on the progress of labour. There has been a more recent Cochrane review on the same subject, epidural versus non‐epidural, which includes opioids as the non‐epidural arm.	The topic of this review is covered in a recently updated Cochrane review.
Halpern 2005a	This is a well conducted review which updates earlier publications by same author.	The topic of this review is covered in a recently updated Cochrane review.
Halpern 2003b	This is not a systematic review.	This is not a systematic review.
Halpern 2005b	This is a narrative review considering findings from other systematic reviews and individual RCTS. It was not clear that there was a systematic search or assessment of individual study quality. The review focuses on PCEA vs a continuous infusion. The review also discusses studies where PCEA plus a continuous background infusion are compared with PCEA alone; and examines different types of PCEA drugs.	This is not a systematic review.
Halpern 2009	This review used systematic methods to assess different types of patient controlled epidural analgesia. The search methods were described (search 1998 to 2008). The review examined a range of different comparisons: 1. PCEA with background infusion vs no background infusion 2. PCEA ropivacaine vs PCEA bupivacaine 3. High vs low PCEA background doses/ lockout times and bolus doses, and different methods of administering drugs. There was no meta‐ analysis. Main findings for each study are set out in tables and summarised in the text.	No data available from meta‐analyses.
Hodnett 2002	This review focuses on all of the primary outcomes of the overview but examines broader questions and draws on descriptive studies. It provides a very useful summary of literature on satisfaction with pain relief .	Not a systematic review including only RCTs.
Huang 2002	This review examines economic issues relating to pain relief in labour a topic which is rarely addressed in trials.	This is not an effectiveness review.
Huntley 2004	This is a review focusing on a range of complementary and alternative techniques for pain relief in labour (acupuncture, hypnosis, biofeedback, sterile water injection and massage along with “respiratory autogenic training”). The review included clear inclusion, exclusion criteria, a search strategy and independent data extraction. There was an assessment of methodological quality (Jadad score). The review included RCTs and quasi RCTs. There was no meta‐analysis due to “statistical heterogeneity amongst the included studies. Results are set out in tabular and narrative form.	This review covers areas already covered in included Cochrane reviews.
Koehn 2002	This is a review looking at studies examining childbirth education/ antenatal classes. The reviewer used a systematic search mechanism although it was not clear how studies were selected for inclusion. The review included both qualitative and quantitative studies but 11/12 studies were descriptive and there was one before and after study. No RCTs were included. There was no systematic evaluation of  risk of bias.Some of the included studies included outcomes relating to pain perception and satisfaction with the childbirth experience, but this was not the main focus of the review. There was no meta analysis or quantitative summary of findings. Results were reported in narrative form and in descriptive tables.	This is not a systematic effectiveness review. Narrative summary of findings from mainly descriptive studies.
Kotaska 2006	This review examines epidural versus parenteral opiates. The review included a search of MEDLINE and the The Cochrane Library. There was no systematic assessment of risk of bias. Results were reported in tables and in the text. A recently updated Cochrane review covers the same topic.	A recently updated Cochrane review covers the same topic.
Kuczkowski 2004	This is not a systematic review, it is a general summary of the literature on regional analgesia.	This is not a systematic review.
Lally 2008	This review used systematic methods but it is not an effectiveness review and included both qualitative and quantitative studies describing women’s perceptions of pain relief during childbirth. Results were summarised in tables and the text.	This review included non‐randomised studies.
Larkin 2009	This is not a systematic review but a qualitative analysis of papers reporting women’s experiences of childbirth.	This is not a systematic review.
Lee 2004	Systematic review examining acupuncture for pain relief in labour. There was a comprehensive search of 7 databases; assessed methodological quality.  All included studies are in more recent Cochrane systematic review.	A recently updated Cochrane review covers the same topic.
Lee 2011	This is not a systematic review but a letter relating to Cho 2010.	This is not a systematic review.
Leeman 2003a	This paper focused on non‐pharmacological methods; It was not clear that this was a systematic review, there was no description of review methods. It was not clear if there was a search strategy. There was some description of the quality of the included studies but this was not systematic. There was no meta‐analysis. Findings were set out in tables and text. The review included Cochrane and other systematic reviews along with other RCTs. It focused on support in labour, sterile water injection, massage, baths and warm water. This review has been superceded by more recent Cochrane reviews.	This is not a systematic review, rather a narrative summary of findings from reviews and trials.
Leeman 2003b	This is a broad overview of reviews and RCT evidence.	This is not a systematic review.
Leighton 2002	This is an update of a well‐conducted systematic review (Halpern 1998) . The review focuses on epidural vs parenteral opioids in labour in relation to progress in labour and rate of caesarean section. A systematic search was carried out (1980‐2001) and details of the search strategy and results of the search are provided. There was independent data extraction by two reviewers and a systematic assessment of quality (Jadad score). The review includes meta‐analysis. This review is now out of date and has been superseded by a more recent Cochrane review.	Superseded by more recent Cochrane review.
Leighton 2003	This is not a report of a systematic review. This paper discussed a range of study designs and considered the evidence relating to labour outcomes.	Not a systematic review but draws on findings of earlier systematic review by same author.
Lieberman 2002	This review included a search strategy and systematic methods for extracting data. There was no systematic assessment of study quality using a domain‐based risk of bias assessment tool, rather the strengths and weaknesses of study designs and analyses were considered. The review looked at both RCTs and observational studies comparing epidural vs opioids and epidural vs no epidural.  Outcomes included rates of CS, assisted delivery, duration of labour and adverse neonatal outcomes. More recent Cochrane reviews have examined these comparisons.	More recent Cochrane reviews examine the same comparisons in RCTs.
Littleford 2004	This is a thorough review of a range of methods for pain relief in labour. The main focus of the review is on adverse effects of analgesia on the fetus and newborn. Although there was a systematic literature search there was no systematic assessment of risk of bias. The review cited other reviews and included discussion of both randomised and non‐randomised studies. There was no meta‐analysis and results are presented in narrative form.	Not a systematic review.
Liu 2004	This systematic review examined low‐dose epidural compared with opioids in nulliparous women. Outcomes included rates of CS, assisted delivery, duration of labour. Systematic methods; search strategy described, included RCTs only, systematic assessment of study quality using Scottish intercollegiate guideline network checklist (which includes the same broad areas of risk of bias as the Cochrane risk of bias tool); systematic methods for data extraction and meta‐analysis. The focus is on nulliparous women only and the comparison has been examined in a more recent Cochrane review.	More recent Cochrane review available.
Lopard 2006	This is not a systematic review. It was not clear that there was a systematic search strategy or clear inclusion and exclusion criteria. There was no systematic assessment of risk of bias. The results are reported as a narrative summary.	This is not a systematic review.
Marucci 2007	This review looks at epidural and combined spinal epidural in nulliparous women. The main outcomes are CS, assisted delivery and neonatal and newborn outcomes. Included both RCTs and cohort studies. The review used systematic methods; the search strategy was described (1990‐2006). The studies were assessed for quality using standard measures (Jahad score for trials). There were standard methods used for data collection and meta‐analysis was performed.	Recently up‐dated Cochrane reviews covers the same area.
Mayberry 2002	This review looks at adverse effects of epidural. Included RCTs. The review used systematic methods; the search strategy was described (1990‐2000). The studies were assessed for quality. Standard methods were used for data collection. Meta‐analysis was not performed rather the results are described narratively. Recently up‐dated Cochrane reviews cover the same area.	Topic covered in recently updated Cochrane reviews.
Minty 2007	This review focuses on intrathecal analgesia as an alternative to epidural. There was a systematic search and the strategy is described. The review includes all study types (reviews, RCTs and observational studies) and there was no clear systematic assessment of the quality of the evidence. The review covers a topic not covered by Cochrane reviews but without a clear assessment of risk of bias results are difficult to interpret.	The review includes a range of study designs.
Morton 1994	This review looks at epidural in nulliparous women. The main outcomes are CS, assisted delivery and neonatal and newborn outcomes. Included both RCTs and other types of studies. The review used some systematic methods; the search strategy was described There were standard methods used for data collection and meta‐analysis was performed. There was no systematic assessment of study quality and risk of bias. Recently up‐dated Cochrane reviews cover the same area.	Review includes non‐randomised studies, no systematic assessment of study quality. Topic covered in more up to date Cochrane reviews.
Nystedt 2004	This review looks at the use of epidural.. Included both RCTs and other types of studies. The review used some systematic methods; the search strategy was described. The studies were assessed for quality based on study design  (high, moderate or low scientific quality) but there was no systematic assessment of risk of bias. Recently up‐dated Cochrane reviews cover the same area	Recently up‐dated Cochrane reviews cover the same area.
Reynolds 2002	This review  examines epidural vs parenteral opioids; the primary focus is on studies reporting fetal acid‐base as an outcome. The review includes both randomised trials and non‐randomised studies. A search strategy is described but there did not appear to be any systematic assessment of study quality.  The topic of this review is covered in a recently updated Cochrane review.	The topic of this review is covered in a recently updated Cochrane review.
Reynolds 2010	This is not a systematic review but is a general narrative summary of methods of pain relief in labour and their effects on the baby.	This is not a systematic review.
Rosen 2002a	This review looks at paracervical block. A search strategy was described but the author describes the review as non‐exhaustive. The search included MEDLINE and the Cochrane library.  The studies included RCTs to examine the effects of analgesia on fetal bradycardia but other studies were included to describe adverse effects. There was no systematic assessment of study quality. The topic of this review has been covered in a recently updated Cochrane review.	The topic of this review has been covered in a recently updated Cochrane review.
Rosen 2002b	This review looks inhaled analgesia. A search strategy was described. The search included MEDLINE and The Cochrane Library. The studies included RCTs but other studies were included to describe adverse effects. It was not clear that there was a systematic assessment of study quality but included studies were described as “low to moderate risk of bias”. The topic of this review has been covered in a recently updated Cochrane review.	The topic of this review has been covered in a recently updated Cochrane review.
Sharma 2003	This review examines epidural analgesia drawing on evidence from randomised trials and non‐randomised studies. It is not a systematic review and it was not clear that there was a search strategy or a systematic assessment of study quality.	This not a systematic review. Regional analgesia is covered in recently updated Cochrane Reviews.
Sharma 2004	This is not a systematic review. This paper reports findings of a retrospective analysis of individual patient data collected in a series of trials over a 7 year period in the same hospital; a subset of nulliparous women are included in the sample in this meta‐analysis. There was no search and no systematic assessment of risk of bias.	This is not a systematic review.
Shiflett 2011	This is not a review. It is a letter commenting on the findings of another review. Cho – acupuncture review.	This is not a review.
Simkin 2002	This review focuses on five methods to relieve pain in labour including broad based interventions such as continuous support in labour, warm baths, maternal positions and mobility in labour and massage and intradermal water. It included RCTs and non‐randomised studies including before and after studies. There was a search strategy but there was no clear assessment of risk of bias. There was no meta‐analysis. Results were presented in narrative form and in tables. The review includes broad base interventions which we have not included as methods of pain relief in labour; massage and water injections are covered in recently updated Cochrane reviews.	Includes non randomised studies and focuses on broad based interventions.
Simkin 2004a	This overview focuses on 13 non‐pharmacological methods to relieve pain in labour including broad based interventions such as continuous support in labour, warm baths, maternal positions and mobility in labour and massage and intradermal water. It draws on findings from a series of systematic reviews (including Cochrane reviews). There was a search strategy but there was no clear assessment of risk of bias in the reviews included. There was no meta‐analysis. Results were presented in narrative form and in tables. The review includes broad base interventions which we have not included as methods of pain relief in labour; massage and water injections and relaxation methods are covered in recently updated Cochrane reviews.	This is not a systematic review. It is a narrative review.
Sleth 2006	This is not a systematic review. There was a search strategy but the more recent data was selected to underpin this discussion of paracervical block. The topic is covered in a recently updated Cochrane review. (Assessment from English abstract; original full article published in French).	Not a systematic review. Cochrane review covers the same topic.
Smith 2009	This review looks at acupuncture during pregnancy and childbirth. It was carried out by the author of a recently updated Cochrane review on acupuncture in labour included in this overview.	Topic covered in recently updated Cochrane review.
Thavaneswaran 2006	This systematic review looks at the safety and efficacy of thoracic and lumbar paravertebral block in surgical patients. The review does not examine pain relief during labour.	This review examines pain relief for surgery (not during childbirth).
Thorp 1996	This review included evidence from both RCTs and non‐randomised studies. There was a search strategy but no systematic assessment of risk of bias or study quality. The review focuses on epidural analgesia which is covered in recently updated Cochrane reviews.	The review focuses on epidural analgesia which is covered in recently updated Cochrane reviews.
Van De Velde 2005	This is not a systematic review. It is a narrative review of various types of neuraxial analgesia and focuses specifically on bradycardia.	This is not a systematic review.
Van de Velde 2009	This is not a systematic review but a general narrative summary and discussion of methods of neuraxial analgesia in labour.	This is not a systematic review.
Van der Vyver 2002	This is a systematic review of RCTs comparing PCEA versus Continuous Infusion for labour.	This topic is covered by more recent reviews on epidural.
Writer 1998	This is not a systematic review – a report of 6 RCTs which were conducted and then the results pooled in a meta‐analysis.	This is not a systematic review.
Wunsch 2003	This literature review includes animal and medical studies, case reports, not RCTs.  Review of pain in pregnancy, not labour and addiction medicine.	This is not a systematic review.
Zhang 1999	This review included both RCTs and observational studies. Search date up to 1997.	This topic is covered by more recent Cochrane reviews on epidural.
Zhou 2008	This review includes RCTs comparing local versus systemic application of opioids for labour analgesia.	This topic is covered by a more recent Cochrane review.

CS: Caeserean section; PCEA: Patient Controlled Epidural Analgesia; RCT: randomised controlled trial