Questions and answers: optimising systematic reviews by considering synthesis questions and methods other than meta-analysis

Systematic reviews are used to collate and synthesise research about health interventions, and inform decisions by clinicians, consumers, policy makers and researchers. Two critical steps in synthesis were investigated: defining the specific questions addressed in the review, and selecting appropriate synthesis methods to answer those questions. A need to improve reporting of both synthesis questions and synthesis methods in published systematic reviews was found, which is important for reviews to be transparent and useful for decision makers; an understanding of statistical methods when meta-analysis is not possible was gained; and guidance on how to report synthesis questions was developed.