Association of proton‐pump inhibitor use with adverse health outcomes: A systematic umbrella review of meta‐analyses of cohort studies and randomised controlled trials

The aim was to perform an umbrella review to summarise the existing evidence on proton-pump inhibitor (PPI) use and adverse outcomes and to grade the certainty of evidence.Electronic databases were searched up to July 2021 for meta-analyses of cohort studies and/or randomised controlled trials (RCTs). Summary effect sizes from a random-effects model, between-study heterogeneity, 95% prediction interval, small-study effect, excess significance...