Assessing the magnitude of changes from protocol to publication-a survey on Cochrane and non-Cochrane Systematic Reviews

Ref ID 932
First Author M. Siebert
Journal PEERJ
Year Of Publishing 2023
URL https://peerj.com/articles/16016/
Keywords • Non-Cochrane reviews
• Transparency
• Protocols
• Cochrane
Problem(s) • Undocumented or unjustified deviations to the review protocol
• Cochrane reviews more rigorous/higher quality than non-Cochrane reviews
Article Type Empirical
Article Subtype Cross-sectional survey/Methodological systematic review
First Author Country United States
Checklists • AMSTAR 2
Aim To assess the completeness of reporting of deviations from the protocol for both Cochrane and non-Cochrane systematic reviews indexed in PubMed and Cochrane databases in 2018.
Level of Investigation Analytical
Summary of Findings From 194 included systematic reviews (97 Cochrane and 97 non-Cochrane systematic reviews) indexed in PubMed and Cochrane databases in 2018. More than half of each sub-sample, 54.6% of Cochrane systematic reviews and 67.0% of non-Cochrane systematic reviews had changes in PICOS elements (ARR 12.4% [−1.3%; 26.0%]). Most changes related to the primary outcome whatever the type of systematic review. Only 3/119 (4.2%) of changes in PICOS items were reported in non-Cochrane systematic reviews, compared to 62/108 (57.4%) to Cochrane systematic reviews (ARR 53.2% [43.2%; 63.2%]).
Number of systematic reviews included 194
Number of eligible systematic reviews assessed 987