The PRISMA 2020 checklist still has 27 items. These correspond to the items in the previous checklist. The wording of the items has been revised for clarity and some of them now contain sub-items that reflect advances in methods since the publication of the 2009 checklist. PRISMA 2020 has extra guidance on synthesis and assessing certainty in the body of evidence. It also has guidance on the use of automation tools, competing interests of review authors, and the availability of data. The main changes are as follows:

1. Abstract reporting checklist: previously an extension, this is now in the main guideline.
2. Methods section: The ‘Protocol and registration’ item has moved to a new ‘Other’ section and a sub-item has been added.
3. Methods section: The ‘Search’ item now recommends that authors present full search strategies for all databases.
4. Methods section: The ‘Selection process’ item now emphasises the reporting of how many reviewers screened each record and each report retrieved, whether they worked independently and details of any automation tools used.
5. Methods section: ‘Data items’ now includes a sub-item (#10a).
6. Methods section: ‘Synthesis methods’ now includes six sub-items (#13a–13f).
7. Results section: ‘Study selection’ now includes a sub-item (#16b).
8. Results section: ‘Results of syntheses’ now includes four sub-items (#20a–20d).
9. Methods section and Results section: New items recommend reporting the methods for and results of an assessment of certainty (or confidence) in the body of evidence for an outcome (#15 and #22).
10. Other information: A new item recommends that authors declare any competing interests (#26).
11. Other information: A new item recommends that authors state whether data used in the review are publicly available and if so, where they can be accessed (#27).

PRISMA 2020 also has an updated flow diagram template. It has optional boxes that are applicable for review updates and reviews that identify new studies via methods other than searching databases and registers. To reflect this, the PRISMA website now has four variations of the flow diagram template to choose from. The checklist and the flow diagram can be completed using new apps.