Metformin and health outcomes:An umbrella review of systematic reviews with meta-analyses

Background:\ud \ud The objective was to capture the breadth of outcomes that have been associated with metformin use and to systematically assess the quality, strength and credibility of these associations using the umbrella review methodology.\ud \ud Methods:\ud \ud Four major databases were searched until 31 May 2020. Meta‐analyses of observational studies and meta‐analyses of randomized controlled trials (RCTs) (including active and placebo control arms) were included.\ud \ud Results:\ud \ud From 175 eligible publications, we identified 427 different meta‐analyses, including 167 meta‐analyses of observational studies, 147 meta‐analyses of RCTs for metformin vs placebo/no treatment and 11…