Rapid reviews may produce different results to systematic reviews: a meta-epidemiological study

OBJECTIVE: To simulate possible changes in systematic review results if rapid review methods were used. STUDY DESIGN AND SETTING: We recalculated meta-analyses for binary primary outcomes in Cochrane systematic reviews, simulating rapid review methods. We simulated searching only PubMed, excluding older articles (5, 7, 10, 15, and 20 years before the search date), excluding smaller trials (20% could be tolerated. This could be the case in scoping reviews, resource limitation, or where syntheses are needed urgently. Other situations, such as clinical guidelines and regulatory decisions, favor more comprehensive systematic review methods.