PRISMA 2020 and PRISMA-S: common questions on tracking records and the flow diagram

The PRISMA 2020 and PRISMA-S guidelines help systematic review teams report their reviews clearly, transparently, and with sufficient detail to enable reproducibility. PRISMA 2020, an updated version of the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) statement, is complemented by PRISMA-S, an extension to PRISMA focusing on reporting the search components of systematic reviews. Several significant changes were implemented in PRISMA 2020 and PRISMA-S when compared with the original version of PRISMA in 2009, including the recommendation to report search strategies for all databases, registries, and websites that were searched. PRISMA-S also recommends reporting the number of records identified from each information source. One of the most challenging aspects of the new guidance from both documents has been changes to the flow diagram. In this article, we review some of the common questions about using the PRISMA 2020 flow diagram and tracking records through the systematic review process.