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 Cochrane
Protocols
Transparency
Non-Cochrane reviews
Problem(s) Undocumented or unjustified deviations to the review protocol
Cochrane reviews more rigorous/higher quality than non-Cochrane reviews
Number of systematic reviews included 194
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%]).
Did the article find that the problem(s) led to qualitative changes in interpretation of the results? Not Applicable
Are the methods of the article described in enough detail to replicate the study? Yes