title: Computing power and sample size for informational odds ratio.
abstract: The informational odds ratio (IOR) measures the post-exposure odds divided by the pre-exposure odds (i.e., information gained after knowing exposure status). A desirable property of an adjusted ratio estimate is collapsibility, wherein the combined crude ratio will not change after adjusting for a variable that is not a confounder. Adjusted traditional odds ratios (TORs) are not collapsible. In contrast, Mantel-Haenszel adjusted IORs, analogous to relative risks (RRs) generally are collapsible. IORs are a useful measure of disease association in case-referent studies, especially when the disease is common in the exposed and/or unexposed groups. This paper outlines how to compute power and sample size in the simple case of unadjusted IORs.
authors.affiliation: Center for Health Disparities Research and Department of Public Health, Brody School of Medicine, Greenville, NC 27858, USA. jimmy.efird@stanfordalumni.org.
authors.forename: Jimmy T
authors.initials: JT
authors.lastname: Efird
mesh_terms: D003627:Data Interpretation, Statistical; D006801:Humans; D015233:Models, Statistical; D016017:Odds Ratio; D012306:Risk; D018401:Sample Size