Explicit and reproducible: how to assess the quality of the evidence in a systematic review
Andrew Clegg, Paul Hewitson, and Ruairidh Milne teach you how to ask the right questions
Reviews provide summaries of evidence to answer important practice and policy questions without readers having to spend the time and effort to summarise the evidence themselves.
Like other research reports, reviews vary greatly, ranging from unstructured reviews (for example, editorials or journalistic reviews) to systematic reviews (for example, those produced by the Cochrane Collaboration). Unstructured reviews, often produced by experts in the subject area, are usually based on unscientific, subjective, and non-replicable methods of information collection and interpretation. In contrast, systematic reviews have explicit, scientific, and comprehensive descriptions of their objectives and methods (box). It is important that those using reviews to inform practice and policy are able to judge what makes a good quality review.1
A number of checklists have been published for assessing the quality of systematic reviews.26 In our opinion, they all have strengths and limitations. For that reason, we make no apology for presenting below the