Health & Environmental Research Online (HERO)


Print Feedback Export to File
758718 
Journal Article 
What's the relative risk? A method of correcting the odds ratio in cohort studies of common outcomes 
Zhang, J; Yu, KF 
1998 
Yes 
JAMA: Journal of the American Medical Association
ISSN: 0098-7484
EISSN: 1538-3598 
280 
19 
1690-1691 
English 
9832001 
Logistic regression is used frequently in cohort studies and clinical trials. When the incidence of an outcome of interest is common in the study population (>10%), the adjusted odds ratio derived from the logistic regression can no longer approximate the risk ratio. The more frequent the outcome, the more the odds ratio overestimates the risk ratio when it is more than 1 or underestimates it when it is less than 1. We propose a simple method to approximate a risk ratio from the adjusted odds ratio and derive an estimate of an association or treatment effect that better represents the true relative risk.