How to Use an Article About Harm

Are the results valid?

• Were there clearly identified comparison groups that were similar with respect to important determinants of outcome other than the one of interest?
• Were the exposures and outcomes measured in the same way in the groups being compared?
• Was followup sufficiently long and complete?
• Is the temporal relationship correct?
• Is there a dose-response gradient?

What are the results?

• How strong is the association between the exposure and outcome?
• How precise is the estimate of the risk?

Will the results help me in caring for my patients?

• Are the results applicable to my practice?
• What is the magnitude of the risk?
• Should I attempt to stop the exposure?

Levine M, et al; for the Evidence-based Medicine Working Group. User's Guides to the Medical Literature IV. How to Use an Article About Harm. JAMA, 1994;271(20):1615-1619.