2. Appraising the relevance of results

2.3 The eight steps

3. Which factor is being studied ?

The factor being studied is the exposure or the intervention that is deemed to affect a health problem, a disease, or a clinical condition.

The reviewer must know how the factor or factors have been measured, if all the relevant factors have been considered, and if the same method of measuring has been applied on all subjects and all groups. The reviewer must also be able to measure the quality (variability, blind trial, etc.).

If the factor being studied is a diagnostic test, can it be independently compared with a gold standard?