Assessing the risk of selection bias in a systematic review which includes non-randomised studies (NRS)

Tags: Workshop
Shea B1
1Cochrane Non-Randomised Studies Methods Group, Canada

Objectives:

The workshop aims to improve awareness of key issues about the risk of selection bias when including NRS in systematic reviews of interventions.

Description:

This workshop (and another) is aimed at review authors intending to include non-randomised studies (NRS) in Cochrane systematic reviews and editors involved with such reviews. The Collaboration recommends that review authors consider and justify whether or not to include NRS for all research questions. Decisions to include NRS may arise when there are inadequate or no RCTs but where the question addressed by the review is a considered a priority. Evaluations of public health and non-pharmacological interventions may have these characteristics. Participants will mainly work in small groups to apply a NRSMG checklist highlighting important considerations, including prior specification of relevant confounding domains, whether or not a domain is likely to give rise to confounding in a study and, if yes, the care with which findings were controlled the confounding domain. The implications of varying amounts and quality of information from primary NRS will be discussed. Varying amounts and quality of information is also the norm for systematic reviews of RCTs, so the discussion will contrast the implications for systematic reviews of NRS and RCTs.