Extracting data for a systematic review of non-randomised studies

Article type
Authors
Reeves B, Wells G
Abstract
This workshop is aimed at reviewers and editors who are considering whether or not to include non-randomised studies (NRS) in Cochrane systematic reviews when there are no RCTs, only poor RCTs or very few small RCTs but where an answer to the review's question is a priority.
Cochrane reviews usually exclude NRS because of concern that the data are biased. The workshop will focus on draft guidance produced by the NRS Methods Group (NRSMG): first, participants will consider the kinds of information that the NRSMG recommends extracting from primary studies; second, participants will investigate the availability and quality of the information required in a sample primary study (previously included in a systematic review of NRS). Three instruments will be used for data extraction about:

a.
study design (a checklist developed by the NRSMG)
b.
the Newcastle-Ottawa Scale (for quality assessment of NRS)
c.
form for extracting data on study findings (adapted from a form used previously for a systematic review of NRS).

The implications of varying amounts and quality of information from primary NRS for systematic reviews of 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.

Target audience: Review authors and editors who are considering the inclusion of non-randomised studies in Cochrane reviews.

Style: Training workshop