Search strategy

A comprehensive literature search was performed using the following databases: PubMed\Medline, Embase, Cochrane Register of Controlled Trials, Web of Science Core Collection, and CINAHL from inception through July 30, 2019 to identify all relevant articles. Controlled subject terms and keyword synonyms for the concepts of colonoscopy, adenoma/polyp detection rate and propofol sedation were developed for PubMed and translated to the vocabularies and syntax of the other databases. The search strategy was created and performed by a librarian (W.L.S.) and cross checked by another reviewer (M.A.). Bibliographic references for included articles were also screened. Relevant articles for final data extraction were shortlisted by two reviewers (M.A. and S.W.). PRISMA and MOOSE guidelines were used to select the final articles. The detailed search strategy for PubMed is highlighted in Supplementary Table 1 .