Questions to Ask Yourself
Are the results valid?
1. Except for the exposure under study, were the compared groups similar to each other?
2. Were the outcomes and exposures measured in the same way in the compared groups?
3. Was follow-up sufficiently long and complete?
Reasons for incomplete follow-up?
Risk factors similar in those lost and not lost to follow-up?
4. Is the temporal relationship correct?
Exposure preceded outcome?
5. Is there a dose-response relationship ?
Risk of outcome increases with quantity or duration of exposure?
What are the results?
1. How strong is the association between exposure and outcome?
2. How precise is the estimate of risk?
3.Did the study have a sufficiently large sample size?
Will the results help me in patient care?
1. Can the results be applied to my patients?
2. What is the magnitude of the risk?
Absolute risk increase (and its reciprocal)?
3. Should I attempt to stop the exposure?
Strength of evidence?
Magnitude of risk?
Adverse effects of reducing exposure?