Most Cochrane Reviews consider evidence on the effects of health or healthcare interventions. These reviews focus primarily on randomized studies as the most robust research design for assessment of the effects of interventions. Where evidence is unlikely to be found in randomized studies, for example for many adverse effects of interventions, or for large-scale interventions such as in public health or organizational change, reviews include non-randomized studies. Intervention reviews may additionally address broader issues such as economic issues or patient experiences of the intervention.
Cochrane has recently developed quality standards for the conduct and reporting of reviews. These standards summarize attributes for the conduct, and reporting, of reviews of interventions as set out in this Handbook (see Chapter 2, Section 2.4).