concordance probability

Concordance probability is a measure used in statistics to evaluate how well a predictive model distinguishes between different outcomes. Imagine predicting whether patients will develop a disease; a high concordance probability means the model correctly ranks individuals, so those who actually get the disease tend to have higher predicted risks than those who don't. It ranges from 0.5 (no better than chance) to 1 (perfect prediction). Essentially, it reflects the model's ability to accurately order or prioritize cases according to their likelihood of an event occurring.