title: Prevalence odds ratio versus prevalence ratio: choice comes with consequences.
abstract: Odds ratio, risk ratio, and prevalence ratio are some of the measures of association which are often reported in research studies quantifying the relationship between an independent variable and the outcome of interest. There has been much debate on the issue of which measure is appropriate to report depending on the study design. However, the literature on selecting a particular category of the outcome to be modeled and/or change in reference group for categorical independent variables and the effect on statistical significance, although known, is scantly discussed nor published with examples. In this article, we provide an example of a cross-sectional study wherein prevalence ratio was chosen over (Prevalence) odds ratio and demonstrate the analytic implications of the choice of category to be modeled and choice of reference level for independent variables. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Medicine, Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL, U.S.A.
authors.forename: Ashutosh R
authors.initials: AR
authors.lastname: Tamhane
authors.affiliation: Department of Medicine, Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL, U.S.A.|Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL, U.S.A.
authors.forename: Andrew O
authors.initials: AO
authors.lastname: Westfall
authors.affiliation: Department of Medicine, Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL, U.S.A.
authors.forename: Greer A
authors.initials: GA
authors.lastname: Burkholder
authors.affiliation: Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL, U.S.A.
authors.forename: Gary R
authors.initials: GR
authors.lastname: Cutter
mesh_terms: D003430:Cross-Sectional Studies; D006801:Humans; D016017:Odds Ratio; D015995:Prevalence; D012107:Research Design; D012306:Risk
keywords: association; odds ratio; prevalence odds ratio; prevalence ratio; risk ratio