Objectives: To introduce the different forms of bias that can affect systematic review results, and the methods that can be used to detect and address these biases in randomized controlled trials (RCTs).
Description: The results of a systematic review can be distorted if bias has been introduced into the review process at any stage (e.g. biased location and selection of included studies, high risk of bias in the results of included studies). Accordingly, investigation of the presence, degree, and nature of bias is recommended as a routine component of the systematic review process.
The Cochrane Methods - Bias Group (BMG) draws together researchers interested in this field, and the Cochrane Handbook contains chapters on 'Assessing risk of bias in included studies' and 'Addressing reporting biases'. The workshop will largely draw upon the work of members of the BMG.
Using examples, we will discuss and explore potential biases that might be introduced in RCTs into reviews, with an emphasis on the effects of flaws in the methodology of included studies. We will discuss how review authors should incorporate risk of bias assessments in the statistical analysis and conclusions of the systematic review. The workshop will consist of presentations and discussions with and among participants. Participants will be encouraged to discuss any perceived challenges in using the current Cochrane 'Risk of bias' tool in systematic reviews.