Validation of a risk function to predict mortality in a VA population with coronary artery disease

A multivariate risk function based on the Cox model was developed in the VA Study of Coronary Artery Bypass Surgery to predict the survival of patients with stable angina pectoris. The methods used in developing and evaluating the performance of the risk function (validation) are described. Performance was evaluated internally by the methods of resubstitution, half-sample replication, and jackknifing, and externally by use of an independent patient population.