Tools for critically appraising different study designs, systematic review and literature searches

A Critical Appraisal Tool (CAT) allows the methodological quality of a study/process to be assessed, which, in turn, influences the reliability of the evidence produced by such a study/process. The European Food Safety Authority (EFSA) Science Strategy 2012–2016 emphasises the importance of strengthening the scientific basis for risk assessment and monitoring. Under this framework, EFSA started the PROMETHEUS project (PROmoting METHods for Evidence Use in Scientific assessments), aiming to further improve the methods for “dealing with data and evidence” in EFSA scientific assessments and to increase their consistency. CATs providing structured and consistent guidance on assessing the methodological quality of a study/process play a key role in this context. This report provides a series of CATs containing a comprehensive list of items to appraise the following: (i) systematic reviews of intervention studies; (ii) randomised controlled trials in humans; (iii) genetically modified plant equivalence studies; and (iv) extensive literature searches. They focus on the risk of bias/appropriateness of the design /conduct of the item under consideration and not on how the item has been reported. The report does not provide detailed guidance on how the items should be appraised. This may be considered by EFSA in a second step, together with the definition of approaches for the prioritisation of the items under assessment.