CA - SR - Applicability

Systematic reviews have the potential to be the highest level of evidence about a given clinical topic, but only if:

- they are performed well (the validity issues mentioned above)
- they include high quality evidence themselves.

Be careful about drawing conclusions from systematic reviews. Importantly, learn to distinguish the difference between:

- Proof of absence - the high quality review found high-quality evidence that, when pooled, shows no overall difference between the intervention and the control.
- Absence of proof - the high quality review found TOO LITTLE high-quality evidence to make a determination about the effect of the intervention.

Heterogeneity - sometimes the discussion of heterogeneity in the review gives a clue about the applicability of the findings.

- If the review finds that the intervention works when the studies done in a certain population are excluded, then you know not to try to apply that evidence in that population.
- Similarly, if the review shows an intervention is effective, but only contains evidence about a certain population,the heterogeneity statistics might be reassuring, but the review's should generally be limited to the population studied.

General questions about APPLICABILITY are the same as those for a therapy question:

- Is my patient like the patients in the review (look at inclusion and exclusion criteria)?
- Is the intervention feasible in my practice?
- Is the outcome one my patients would care about (patient-oriented evidence)?

Other Systematic Review Things

Validity Issues: