A systematic assessment of Cochrane reviews and systematic reviews published in high-impact medical journals related to cancer

Ref ID 132
First Author M. Goldkuhle
Journal BMJ OPEN
Year Of Publishing 2018
URL https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5875625/pdf/bmjopen-2017-020869.pdf
Keywords Cochrane
Oncology
Non-Cochrane reviews
Problem(s) Cochrane reviews more rigorous/higher quality than non-Cochrane reviews
Unwieldy/ difficult to read
Number of systematic reviews included 561
Summary of Findings 346 Cochrane reviews and 215 non-Cochrane systematic reviews were included. Cochrane reviews consistently met more individual AMSTAR criteria, notably with regard to an a priori design (risk ratio (RR) 3.89; 95% CI 3.10 to 4.88), inclusion of the grey literature and trial registries (RR 3.52; 95% CI 2.84 to 4.37) in their searches, and the reporting of excluded studies (RR 8.80; 95% CI 6.06 to 12.78). Cochrane reviews were less likely to address questions of prognosis (RR 0.04; 95% CI 0.02 to 0.09), use individual patient data (RR 0.03; 95% CI 0.01 to 0.09) or be based on non-randomised controlled trials (RR 0.04; 95% CI 0.02 to 0.09). Citation rates of Cochrane reviews were notably lower than those for high-impact journals (Cochrane reviews: mean number of citations 6.52 (range 0–143); high-impact journal systematic reviews: 74.45 (0–652)). The authors highlight that Cochrane reviews are not limited by word count, unlike high-impact journals. This can aid better reporting but Cochrane reviews being longer reports may also contribute to their lower citation rate.
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? No