The win odds is a distribution-free method of comparing locations of distributions of two independent random variables. Introduced as a method for analyzing hierarchical composite endpoints, it is well suited to be used in the analysis of ordinal scale endpoints in COVID-19 clinical trials. For a single outcome, we provide power and sample size calculation formulas for the win odds test. We also provide an implementation of the win odds analysis method for a single ordinal outcome in a commonly used statistical software to make the win odds analysis fully reproducible.
Keywords: COVID-19; Fligner-Policello; Mann-Whitney; SAS software; Somers’ D C/R; Wilcoxon rank-sum; Win odds; effect size; number needed to treat; power; sample size.