title: Diagnostic strategies.
abstract: A simple model of a universe of disease is presented. It permits the numerical comparison of different diagnostic strategies. Those diagnostic strategies exclusively using laboratory tests of perfect sensitivity and perfect specificity are shown to be inferior to a diagnostic strategy that begins with clinical information of unknown, but imperfect, sensitivity and specificity. This is true, within the model, even if we assume a "perfect world" in which every disease is represented by a "perfect" laboratory test.
mesh_terms: D019411:Clinical Laboratory Techniques; D019937:Diagnostic Techniques and Procedures; D006801:Humans; D008962:Models, Theoretical