Infectious disease trials have long used ordinal outcomes, or ranked categorical scales, to capture the full spectrum of response to an intervention. We review 2 summary statistics for ordinal outcomes: the proportional odds ratio (pOR) and the win probability. The pOR asks: How much more likely is a treated participant to be in an improved category compared with control? The win probability asks: In a random treatment-control pair, what is the chance the treated participant fares better? We also introduce visual companions, the stacked-bar chart and bubble plot, to make ordinal trial results more accessible and interpretable.
Harrison et al. (2026) studied this question.