The DISC Predictive Scales (DPS): efficiently screening for diagnoses.

OBJECTIVE To derive and test a series of brief diagnosis-specific scales to identify subjects who are at high probability of meeting diagnostic criteria and those who may safely be spared more extensive diagnostic inquiry. METHOD Secondary data analysis of a large epidemiological data set (n = 1,286) produced a series of gate and contingent items for each diagnosis. Findings were replicated in a second retrospective analysis from a residential care sample (n = 884). The DISC Predictive Scales (DPS) were then used prospectively as a self-report questionnaire in two studies, in which parents (n = 128) and/or adolescents (n = 208) had subsequent diagnostic interviewing with the Diagnostic Interview Schedule for Children or the Schedule for Affective Disorders and Schizophrenia for School-Age Children. RESULTS All analyses showed that gate item selection was valid and that any missed cases were due solely to inconsistent reports on the same questions. Screening performance of the full scales was shown to be good, and substantial reductions in scale length were not associated with significant changes in discriminatory power. CONCLUSIONS The DPS can accurately determine subjects who can safely be spared further diagnostic inquiry in any diagnostic area. This has the potential to speed up structured diagnostic interviewing considerably. The full DPS can be used to screen accurately for cases of specific DSM-III-R disorders.