Cochrane Skin Group systematic reviews are more methodologically rigorous than other systematic reviews in dermatology

BACKGROUND: The Cochrane collaboration aims to produce high-quality systematic reviews. It is not known whether the methods used in producing Cochrane Skin Group (CSG) reviews result in higher quality reviews than other systematic reviews in dermatology. OBJECTIVES: To determine how the methodological quality of dermatological CSG reviews published in The Cochrane Library and in peer-reviewed journals compare with non-Cochrane systematic reviews. METHODS: Two blinded investigators independently assessed review quality using the 10-item Oxman and Guyatt scale. RESULTS: Thirty-eight systematic reviews (17 Cochrane reviews published in The Cochrane Library, 11 Cochrane reviews published in peer-reviewed journals and 10 non-Cochrane reviews published in peer-reviewed journals) were examined. The Cochrane Library reviews included quality of life (11/17 vs. 1/10, P = 0.014) and adverse outcomes (14/17 vs. 2/10, P = 0.003) more often than non-Cochrane reviews published in peer-reviewed journals. Cochrane reviews published in both peer-reviewed journals and The Cochrane Library were more likely to include comprehensive search strategies (11/11 and 17/17 vs. 6/10, P-values = 0.04 and 0.01), take steps to minimize selection bias (11/11 and 16/17 vs. 3/10, P-values = 0.003 and 0.001) and appropriately assess the validity of all included trials (10/11 and 16/17 vs. 4/10, P-values = 0.04 and 0.007) than non-Cochrane reviews. Overall, Cochrane reviews published both in peer-reviewed journals and in The Cochrane Library were assigned higher quality scores by reviewers than non-Cochrane reviews (median = 6.0 and 6.5 vs. 4.5, P-values = 0.01 and 0.002). CONCLUSIONS: The Cochrane Library systematic review methodology leads to higher quality reviews on dermatological topics.