Biases can lead to under-estimation or over-estimation of the true intervention effect and can vary in magnitude: some are small (and trivial compared with the observed effect) and some are substantial (so that an apparent finding may be due entirely to bias). We define bias as a systematic error, or deviation from the truth, in results. Available from 7.1 IntroductionĬochrane Reviews seek to minimize bias. Cochrane Handbook for Systematic Reviews of Interventions version 6.3 (updated February 2022). In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (editors). Chapter 7: Considering bias and conflicts of interest among the included studies. Review authors should consider source of funding and conflicts of interest of authors of the study, which may inform the exploration of directness and heterogeneity of study results, assessment of risk of bias within studies, and assessment of risk of bias in syntheses owing to missing results.Ĭite this chapter as: Boutron I, Page MJ, Higgins JPT, Altman DG, Lundh A, Hróbjartsson A. Results of meta-analyses (or other syntheses) across studies may additionally be affected by bias due to the absence of results from studies that should have been included in the synthesis. Problems with the design and execution of individual studies of healthcare interventions raise questions about the internal validity of their findings empirical evidence provides support for this concern.Īn assessment of the internal validity of studies included in a Cochrane Review should emphasize the risk of bias in their results, that is, the risk that they will over-estimate or under-estimate the true intervention effect. The second is in the result of the meta-analysis (or other synthesis) of findings from the included studies. The first is in the results of the individual studies included in a systematic review. We draw a distinction between two places in which bias should be considered. Review authors should seek to minimize bias.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |