Three approaches to regression analysis of receiver operating characteristic curves for continuous test results

The accuracy of a medical diagnostic test is typically summarized by the sensitivity and specificity when the test result is dichotomous. Receiver operating characteristic (ROC) curves are measures of test accuracy that are used when test results are continuous and are considered the analogs of sensitivity and specificity for continuous tests. ROC regression analysis allows one to evaluate effects of factors that may influence test accuracy. Such factors might include characteristics of study subjects or operating conditions for the test. Unfortunately, regression analysis methods for ROC curves are not well developed and methods that do exist have received little use to date. In this paper, we propose and compare three very different regression analysis methods. Two are modifications of methods previously proposed for radiology settings. The third is a special case of a general method recently proposed by us. The three approaches are compared with regard to settings in which they can be applied and distributional assumptions they require. In the setting where test results are normally distributed, we elucidate the correspondence between regression parameters in the different models. The methods are applied to simulated data and to data from a study of a new diagnostic test for hearing impairment. It is hoped that the presentation in this paper will both encourage the use of regression analysis for evaluating diagnostic tests and help guide the choice of the most appropriate regression analysis approach in applications.