On tests for equality of predictive values for t diagnostic procedures

Abstract

This paper concerns comparisons of the efficiency of several diagnostic tests, as characterized by the measures of sensitivity (ξ), specificity (η) and predictive value (ρ). We show that hypotheses concerning the equality of predictive values relate only to hypotheses concerning ξ and η and that we can test these by approximate χ² statistics. Data for the cases of t = 2 or 3 diagnostic tests illustrate the method.