Fig. 1

2020 PRISMA flow diagram of the search process undertaken to identify eligible guidelines, with number of records considered or excluded at each stage of the process. The database searches identified 6026 unique records, of which 357 guidelines were identified as eligible for inclusion after screening by two independent reviewers. Searches of websites of 165 organizations, societies, and colleges identified a further 48 eligible guidelines. In total, 405 guidelines were included in this review. From: Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372:n71