Should non-randomised studies of interventions (NRSI) be included in your systematic review of the effects of a health care intervention?; and, if so,
What types of NRSI design may help answer review questions about intervention effects?
It has been developed primarily for systematic reviews of the effects of healthcare interventions in public health. NRSI are defined in the Cochrane Handbook for Systematic Reviews of Interventions as any quantitative study estimating the effects of an intervention (benefit or harm) that does not use randomisation to allocate individuals (or groups of individuals) to intervention groups. This guidance was developed as part of a collaborative programme of work aimed at delivering practical resources to help authors and editors translate guidance from the Cochrane Handbook for Systematic Reviews of Interventions into practice.
May 2024: Cochrane endorsed this guidance document as an optional resource for prospective authors following a recommendation from the Methods Executive, which was informed by the relevant Methods Groups, Cochrane's Methods Support and Review Development Team, a Cochrane Review Group representative and the Methods Executive representative on Cochrane's Editorial Board.
Key resources:
Cochrane Handbook of Systematic Reviews of Interventions, in particular:
Chapter 24 about including non-randomized studies on intervention effects.