PRISMA 2020 Is a Reporting Guideline for Systematic Reviews but Is Often Misused to Guide Review Content.

Introduction: The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) is a reporting guideline aiming to facilitate transparent and accurate reporting in systematic reviews. The latest version, PRISMA 2020, specifies that it is intended for guiding the reporting, not the conduct, of systematic reviews. We examined how often systematic review authors reported having used PRISMA 2020 outside its scope. Methods: We randomly sampled 200 systematic reviews citing PRISMA 2020 and extracted all sentences describing how PRISMA 2020 was used. Two authors independently assessed the extracted sentences and categorised the use of PRISMA 2020 as one of the following options: adequate (i.e., as a reporting guideline), inconclusive (e.g., unclear or ambiguous description) or inadequate (e.g., to guide review conduct). Results: The systematic reviews were published between 2021 and 2024, and 88.0% were published in biomedical journals. More than half (55.5%) of the systematic reviews described using PRISMA 2020 inadequately, typically as a guide for review conduct; 24.0% were categorised as 'inconclusive', and only 20.5% were categorised as 'adequate'. Conclusion: More than half of the systematic reviews described using PRISMA 2020 outside its intended scope. We encourage systematic review authors to use PRISMA 2020 as a reporting guideline. Other resources are available to guide the conduct of systematic reviews, e.g., the Cochrane Handbook for Systematic Reviews of Interventions.