A scoping review identifies comments suggesting modifications to PRISMA-P 2015

Objectives: To identify, summarise, and analyse published comments relevant to the PRISMA-P (Preferred Items for Reporting Systematic reviews and Meta-Analyses Protocols) 2015 reporting guideline for systematic review protocols, with special emphasis on suggestions for guideline modifications.Methods: We included documents (e.g., empirical studies and social media posts) that included comments relevant to PRISMA-P 2015. We searched bibliographic databases (e.g., Embase, MEDLINE, Scopus, from January 1st 2015 to February 2nd 2024) and other sources (e.g., BMJ rapid responses, BMC Blog Network, from January 1st 2015 to April 22nd 2024). Two authors independently assessed documents for inclusion, extracted data, and categorised comments. We categorised comments as ‘suggestion for modification to the wording of an existing PRISMA-P 2015 item’, ‘suggestion for a new item’, ‘suggestion for deletion of an existing PRISMA-P 2015 item’, or ‘additional comment’. We categorised each comment into themes and provided a summary and examples of the proposed suggestions. We analysed the characteristics of the suggestions by describing the rationale and comparing with existing PRISMA-P 2015 guidance.Results: We assessed full text of 1,912 potentially eligible documents and included 28 documents with 38 comments. Eleven comments suggested modifications to existing guideline items. Multiple comments proposed modifications to items related to eligibility criteria (three comments made different suggestions, e.g., one comment suggested to include reporting guidance relating to retracted papers in PRISMA 2020 and we deemed this potentially relevant for systematic review protocols) and data synthesis (three comments made different suggestions, e.g., one comment suggested to add reporting guidance relation to prediction intervals for random-effects meta-analyses in PRISMA 2020 and we deemed this potentially relevant for systematic review protocols). There were 11 comments suggesting new items. The data items section of PRISMA-P 2015 received the most comments (five comments made different suggestions, e.g., three comments suggested to add content on pre-specifying whether authors plan to extract information on funding and conflicts of interest among the included studies). Most of the suggestions provided a rationale directly in the document and around two-thirds of the suggestions addressed content not already included in PRISMA-P 2015.Conclusion: The issues raised provide context to authors, peer reviewers, editors, and readers of systematic review protocols using PRISMA-P 2015 and inform the planned update of the guideline.