Bootstrapping Diagnoses Using Bayes's Theorem. It's Not Worth the Trouble

Many Diagnostic and Statistical Manual of Mental Disorders (DSM-III; American Psychiatric Association, 1980) diagnostic procedures are based partly on the cutting of a symptom count at some predetermined point. Finn (1982)argued that base rates (prevalences) need to be used to modify the number of symptoms required for making a diagnosis. In this brief report, Monte Carlo results show that the improvements in diagnostic accuracy of such flexible diagnostic rules over DSM-III fixed symptom-count cutting scores are too small to justify their use.