%0 Journal Article
%T Computing Power and Sample Size for Informational Odds Ratio
%A Jimmy T. Efird
%J International Journal of Environmental Research and Public Health
%D 2013
%I MDPI AG
%R 10.3390/ijerph10105239
%X 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.
%K informational odds ratios
%K power
%K sample size
%U http://www.mdpi.com/1660-4601/10/10/5239