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Cited by 404Meta-analysis and systematic reviewsscientometrics and bibliometrics researchPsychology Research and Bibliometrics

The DOI matches its Crossref record; 15 of the 16 references it cites were found in a registry or an index.

Characteristics of meta-analyses and their component studies in the Cochrane Database of Systematic Reviews: a cross-sectional, descriptive analysis

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Davey, Jonathan, Turner, Rebecca M, Clarke, Mike J, Higgins, Julian PT·2011·BMC Medical Research Methodology
DOI 10.1186/1471-2288-11-160PMC PMC3247075
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Abstract

BACKGROUND: Cochrane systematic reviews collate and summarise studies of the effects of healthcare interventions. The characteristics of these reviews and the meta-analyses and individual studies they contain provide insights into the nature of healthcare research and important context for the development of relevant statistical and other methods. METHODS: We classified every meta-analysis with at least two studies in every review in the January 2008 issue of the Cochrane Database of Systematic Reviews (CDSR) according to the medical specialty, the types of interventions being compared and the type of outcome. We provide descriptive statistics for numbers of meta-analyses, numbers of component studies and sample sizes of component studies, broken down by these categories. RESULTS: We included 2321 reviews containing 22,453 meta-analyses, which themselves consist of data from 112,600 individual studies (which may appear in more than one meta-analysis). Meta-analyses in the areas of gynaecology, pregnancy and childbirth (21%), mental health (13%) and respiratory diseases (13%) are well represented in the CDSR. Most meta-analyses address drugs, either with a control or placebo group (37%) or in a comparison with another drug (25%). The median number of meta-analyses per review is six (inter-quartile range 3 to 12). The median number of studies included in the meta-analyses with at least two studies is three (inter-quartile range 2 to 6). Sample sizes of individual studies range from 2 to 1,242,071, with a median of 91 participants. DISCUSSION: It is clear that the numbers of studies eligible for meta-analyses are typically very small for all medical areas, outcomes and interventions covered by Cochrane reviews. This highlights the particular importance of suitable methods for the meta-analysis of small data sets. There was little variation in number of studies per meta-analysis across medical areas, across outcome data types or across types of interventions being compared.

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Figure 1 Illustration of the hierarchy of a 'Data and analyses' section of a Cochrane review. Reproduced with permission from Chapter 4 of the Cochrane Handbook for Systematic Reviews of Interventions.
Figure 1 Illustration of the hierarchy of a 'Data and analyses' section of a Cochrane review. Reproduced with permission from Chapter 4 of the Cochrane Handbook for Systematic Reviews of Interventions.CC BY · PubMed Central
Figure 2 Flow diagram showing eligibility and exclusions of meta-analyses and studies.
Figure 2 Flow diagram showing eligibility and exclusions of meta-analyses and studies.CC BY · PubMed Central

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Research works printed but not linked: 3

  1. Higgins JPT, Green Se: Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.2 [updated September 2009]. 2009, The Cochrane Collaboration
  2. Review Manager (RevMan) [Computer Program]. Version 5.0. 2008, Copenhagen, The Nordic Cochrane Centre, The Cochrane Collaboration
  3. Wood L: The epidemiology of bias in randomized (clinical) controlled trials: a meta-epidemiological study. 2006, University of Bristol

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Metadata

Authors
Davey, J., Turner, R. M., Clarke, M. J., & Higgins, J. P.
Affiliations
  • MRC Biostatistics Unit (GB)
  • Queen's University Belfast (GB)
Corresponding author
Turner, Rebecca M
ORCID
Venue
BMC Medical Research Methodology
Publisher
Springer Science and Business Media LLC
Published
2011-11-24
Volume
11
Issue
1
Pages
160-160
ISSN
1471-2288 (ISSN-L)
DOI
10.1186/1471-2288-11-160
PMC
PMC3247075
OpenAlex
W1965385672
Cited by
404
References
16
Citations by year
2026: 27 · 2025: 32 · 2024: 38 · 2023: 30 · 2022: 23 · 2021: 37 · 2020: 26 · 2019: 29 · 2018: 37 · 2017: 41 · 2016: 31 · 2015: 13 · 2014: 22 · 2013: 9 · 2012: 9
FWCI
3.11
Type
journal article
Language
en
Open access
Licence
Locations
  • BMC Medical Research Methodology (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • UCL Discovery (University College London) (submittedVersion)
  • Research Portal (Queen's University Belfast) (submittedVersion)
  • Explore Bristol Research (submittedVersion)
  • Apollo (University of Cambridge) (submittedVersion, cc-by)
Funders
Medical Research Council (U1052.00.011)
Topics
  • Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
  • Social Sciences › Library and Information Sciences › scientometrics and bibliometrics research
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Psychology Research and Bibliometrics
Keywords
meta-analysis, Cochrane Database of Systematic Reviews, sample size, health interventions
MeSH terms
Cross-Sectional Studies, Humans, Review Literature as Topic, Meta-Analysis as Topic, Databases, Factual, Outcome Assessment, Health Care

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