Epidemiology and Reporting Characteristics of Systematic Reviews

By David Moher, J. Tetzlaff, Andrea C. Tricco, M. Sampson, Douglas G. Altman. PLoS Medicine, 2007

843 citations recorded by the source corpus.

Background Systematic reviews (SRs) have become increasingly popular to a wide range of stakeholders. We set out to capture a representative cross-sectional sample of published SRs and examine them in terms of a broad range of epidemiological, descriptive, and reporting characteristics, including emerging aspects not previously examined. Methods and Findings We searched Medline for SRs indexed during November 2004 and written in English. Citations were screened and those meeting our inclusion criteria were retained. Data were collected using a 51-item data collection form designed to assess the epidemiological and reporting details and the bias-related aspects of the reviews. The data were analyzed descriptively. In total 300 SRs were identified, suggesting a current annual publication rate of about 2,500, involving more than 33,700 separate studies including one-third of a million participants. The majority (272 [90.7%]) of SRs were reported in specialty journals. Most reviews (213 [71.0%]) were categorized as therapeutic, and included a median of 16 studies involving 1,112 participants. Funding sources were not reported in more than one-third (122 [40.7%]) of the reviews. Reviews typically searched a median of three electronic databases and two other sources, although only about two-thirds (208 [69.3%]) of them reported the years searched. Most (197/295 [66.8%]) reviews reported information about quality assessment, while few (68/294 [23.1%]) reported assessing for publication bias. A little over half (161/300 [53.7%]) of the SRs reported combining their results statistically, of which most (147/161 [91.3%]) assessed for consistency across studies. Few (53 [17.7%]) SRs reported being updates of previously completed reviews. No review had a registration number. Only half (150 [50.0%]) of the reviews used the term “systematic review” or “meta-analysis” in the title or abstract. There were large differences between Cochrane reviews and non-Cochrane reviews in the quality of reporting several characteristics. Conclusions SRs are now produced in large numbers, and our data suggest that the quality of their reporting is inconsistent. This situation might be improved if more widely agreed upon evidence-based reporting guidelines were endorsed and adhered to by authors and journals. These results substantiate the view that readers should not accept SRs uncritically.

Subfields: History and Philosophy of Science, Pharmacology, Statistics and Probability

View Paper: https://www.semanticscholar.org/paper/e545753c909f6720973dfbda956821e441c3a38a

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Citations in the corpus

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Expediting systematic reviews: methods and implications of rapid reviews (2010, background): “found that the quality of systematic reviews themselves are inconsistent, thereby blurring lines further between systematic review and rapid review methods [49].”
The impact of outcome reporting bias in randomised controlled trials on a cohort of systematic reviews (2010, background): “Cochrane systematic reviews are internationally recognised as among the best sources, if not the best source, of reliable up to date information on health care.”
A scoping review on the conduct and reporting of scoping reviews (2016, background): “Use of reporting checklists increases transparency of methods, and allows readers to judge validity and reliability and use research appropriately [9, 10].”
Seventy-Five Trials and Eleven Systematic Reviews a Day: How Will We Ever Keep Up? (2010, background): “variously estimated at between six and 16 (Cochrane reviews now include an average of over 12 trials per review [27,28]; M Clarke, personal communication), but many reviews have covered much the same territory.”
How Quickly Do Systematic Reviews Go Out of Date? A Survival Analysis (2007, background): “Finally, Cochrane reviews differ in important respects, such as clinical topic coverage, from other peerreviewed systematic reviews (25).”