$Pooled OR of cohort or nested case-control studies. &Pooled OR of retrospective case-control studies. Ψ The comparison odds ratio, is the ratio of OR1 versus OR2. ORC>1 implies that studies employed
BackgroundThere is considerable debate as to the relative merits of using randomised controlled trial (RCT) data as opposed to observational data in systematic reviews of adverse effects. This meta-an