OBJECTIVES To describe how the methodological quality of primary studies is assessed in systematic reviews and whether the quality assessment is taken into account in the interpretation of results. DATA SOURCES Cochrane systematic reviews and systematic reviews in paper based journals. STUDY SELECTION 965 systematic reviews (809 Cochrane reviews and 156 paper based reviews) published betwee...

Conducting a review of systematic reviews can be challenging, especially when combining quantitative, qualitative and mixed studies reviews. In this methodological discussion paper, we propose (a) typology for categorizing various types (b) an exploration criteria pertaining to three existing critical appraisal tools (ROBIS, AMSTAR 2, MMSR) identify those that could adapted Further work has don...