Risk of bias over time in updates of Cochrane oral health reviews

Faggion, C.M., Jr.; Aranda, L.; Pandis, N.; Alarcón, M.A.; Diaz, K.T.

dc.contributor.author	Faggion, C.M., Jr.
dc.contributor.author	Aranda, L.
dc.contributor.author	Pandis, N.
dc.contributor.author	Alarcón, M.A.
dc.contributor.author	Diaz, K.T.
dc.date.accessioned	2019-07-04T17:00:23Z
dc.date.available	2019-07-04T17:00:23Z
dc.date.issued	2019
dc.identifier.uri	https://hdl.handle.net/20.500.12866/6896
dc.description.abstract	Objectives: To assess the changes in the risk of bias (RoB) across different versions of the same Cochrane systematic review, and to identify characteristics of systematic reviews which may be associated with different RoB scores by means of regression analysis. Methods: We examined changes in RoB ratings in domains of randomized controlled trials (RCTs) and controlled trials (CTs) included in original Cochrane systematic reviews and their updates published in oral health. First, we checked the number of domains assessed for RoB in the different versions of the systematic review. Then, we computed the percentage of different ratings of RoB (low, high and unclear) in these systematic review versions. All data selection, extraction and analysis were conducted independently and in duplicate by two assessors. Time trends were reported in the form of line graphs. We also assessed systematic review characteristics as predictors of RoB scores by means of regression analysis. Results: A total of 173 reviews consisting of the original reviews and their updates were examined. The proportion of different ratings of RoB was kept stable over the different versions. However, in more recent versions, the proportion of unclear RoB slightly increased, and the proportion of high RoB decreased. Cochrane risk of bias domains were a significant RoB score predictor (Likelihood ratio test p-value < 0.001). Conclusions: Methodological improvements in RCTs and CTs included in Cochrane reviews are needed. This comprehensive information on the RoB trend may help oral health researchers improving the methodology related to specific domains. Clinical significance: Methodological improvements are necessary for primary studies included in Cochrane reviews in oral health. The increase of domains rated as unclear RoB is of concern and suggests that strategies should be developed to improve the level of communication between trialists and systematic reviewers.	en_US
dc.language.iso	eng
dc.publisher	Elsevier
dc.relation.ispartofseries	Journal of Dentistry
dc.rights	info:eu-repo/semantics/restrictedAccess
dc.rights.uri	https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es
dc.subject	human	en_US
dc.subject	controlled study	en_US
dc.subject	systematic review	en_US
dc.subject	scientist	en_US
dc.subject	risk assessment	en_US
dc.subject	article	en_US
dc.subject	health	en_US
dc.subject	Bias	en_US
dc.subject	Cochrane tool	en_US
dc.subject	extraction	en_US
dc.subject	Methodological study	en_US
dc.subject	Methods	en_US
dc.subject	Randomized controlled trial	en_US
dc.subject	randomized controlled trial (topic)	en_US
dc.subject	regression analysis	en_US
dc.subject	statistical significance	en_US
dc.subject	Systematic reviews	en_US
dc.title	Risk of bias over time in updates of Cochrane oral health reviews	en_US
dc.type	info:eu-repo/semantics/article
dc.identifier.doi	https://doi.org/10.1016/j.jdent.2018.10.004
dc.subject.ocde	https://purl.org/pe-repo/ocde/ford#3.02.14
dc.relation.issn	1879-176X