title: A deficiency of the odds ratio as a measure of effect size.
abstract: The odds ratio is probably the most widely used measure of association for binary variables. It has many well-recognized advantages and disadvantages vis-à-vis the risk ratio. We demonstrate that for chained or conditional probabilities, odds ratios can behave paradoxically, by failing to show a reinforcement effect that is expressed very clearly when risk ratios are used.
authors.affiliation: Wales College of Medicine, Cardiff University, Heath Park, Cardiff CF14 4YS, UK. Newcombe@cf.ac.uk
authors.forename: Robert G
authors.initials: RG
authors.lastname: Newcombe
mesh_terms: D000293:Adolescent; D017280:Condoms; D003627:Data Interpretation, Statistical; D006801:Humans; D016017:Odds Ratio; D012306:Risk; D012725:Sexual Behavior