Do systematic reviews still exclude studies with "no relevant outcome data"?

Ref ID 470
First Author K. M. Dwan
Journal BMJ
Year Of Publishing 2017
URL https://www.bmj.com/content/358/bmj.j3919.long
Keywords • General medical
• Cochrane
• Multiplicity
• Missing data
Problem(s) • Errors in study inclusion or omission of relevant studies
• Weaknesses identified in some Cochrane reviews
Article Type Editorial
Article Subtype Comment/letter
First Author Country United Kingdom
Aim A research letter highlighting that systematic reviews should no longer exclude studies on the basis of not reporting relevant outcome data, if they fit the review's eligibility criteria. This is because failure to report the outcome of interest is not definitive proof that the outcome was not measured and this is not acknowledged in MECIR. The authors assessed a number of samples of reviews from Cochrane review groups between 2013-2016 to assess the number of excluded studies due to 'no relevant outcome data'.
Level of Investigation Descriptive
Summary of Findings Around 20% of included Cochrane reviews were still excluding studies based on the lack of reporting of outcomes of interest in trial reports which the author highlights potentially contributes to research waste if otherwise eligible studies are discarded based on failure to report outcome data.
Number of systematic reviews included 434
Number of eligible systematic reviews assessed 434
Treatment impacted No
Treatment impacted description
Interpretation impacted Not Applicable
Interpretation impacted description