BAYESIAN-ANALYSIS OF ROC CURVES USING MARKOV-CHAIN MONTE-CARLO METHODS

The authors introduce a Bayesian approach to generalized linear regres sion models for rating data observed in the evaluation of a diagnostic technology. Such models were previously studied using a non-Bayesian approach. In a Bayesian analysis, the difficulties inherent in an ordi nal rating scale are circumvented by using data-augmentation technique s. Posterior distributions for the regression parameters-and thereby f or receiver operating characteristic (ROC) curve parameters and values , for the area under a ROC curve, differences between areas, etc.-may then be computed by Markov-chain Monte Carlo methods. Inferences are m ade in standard Bayesian ways. The methods are exemplified by a study of ultrasonography rating data for the detection of hepatic metastases in patients with colon or breast cancer (previously analyzed) and the results compared.