title: Can we improve the diagnostic efficiency and predictive power of prodromal symptoms for schizophrenia?
abstract: Prodromal symptoms and other variables for a sample of 200 young people who had experienced a first-onset functional psychosis, were analyzed to examine their diagnostic efficiency and predictive power in relation to a diagnosis of schizophrenia. Two different techniques were utilized to generate optimal cut-off points for a number of prodromal symptoms, and optimal decision rules to maximize diagnostic efficiency. The product of the chance-corrected sensitivity and specificity, or the area under the QROC curve, was used to assess the predictive efficiency of a number of prodromal variables, DSM-III-R prodromal variables, pre-psychotic deterioration, pre-morbid functioning, and prodromal duration. The SPAN technique generated a decision rule that performed equivalently to the single variable 'duration of prodrome'. Implications of these results for future research are discussed.
authors.affiliation: Department of Psychiatry, University of Melbourne, Youth Program, Mental Health Services for Kids and Youth, Locked Bag 10, Parkville, Australia. mcgorry@ariel.unimelb.edu.au
authors.forename: P D
authors.initials: PD
authors.lastname: McGorry
authors.forename: D
authors.initials: D
authors.lastname: McKenzie
authors.forename: H J
authors.initials: HJ
authors.lastname: Jackson
authors.forename: F
authors.initials: F
authors.lastname: Waddell
authors.forename: C
authors.initials: C
authors.lastname: Curry
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000209:etiology; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology; D012680:Sensitivity and Specificity