Questions to Ask Yourself
Are the results valid?
1. Was the assignment of patients to treatment randomized?
2. Were all patients who entered the trial properly accounted for and attributed at its conclusion?
3. Were patients, their clinicians and study personnel 'blind' to treatment?
4. Were the groups similar at the start of the trial?
Baseline prognostic factors (demographics, co-morbidity, disease severity, other known confounders) balanced?
If different, were these adjusted for?
5. Aside from the experimental intervention, were the groups treated equally?
What are the results?
1. How large is the treatment effect?
2. Did the study have a sufficiently large sample size?
3. How precise is the estimate of the treatment effect?
Will the results help me in patient care?
1. Can the results be applied to my patients?
Patients similar for demographics, severity, co-morbidity and other prognostic factors?
Compelling reason why they should not be applied?
2. Were all clinically relevant outcomes considered?
Are surrogate endpoints valid?
3. Are the benefits worth the harms and costs?
NNT for different outcomes?