What is PRISMA?

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) is a reporting guideline for systematic reviews. Its 2020 version has a 27-item checklist and a flow diagram showing how many records were identified, removed as duplicates, screened, excluded with reasons, and included. Most journals ask systematic reviews to follow it.

The flow diagram is easy when you count at each stage as you go, and painful to reconstruct at the end.

Extensions exist for scoping reviews (PRISMA-ScR) and other review types.