Relevant evidence

Are the circumstances used in evidence sources different from yours?

Always ask yourself if fair comparisons of interventions were conducted in circumstances that are relevant.

Some evaluations are designed to measure the effect of an intervention under ideal circumstances, for example with subjects that are most likely to benefit, and with highly trained practitioners who deliver the intervention exactly as intended. These comparisons, which are sometimes called explanatory or efficacy studies, may not reflect what happens under usual circumstances.

REMEMBER: Be aware that the results of studies with the aim of finding out if an action can work may overestimate the benefits of an intervention under more usual circumstances.