Can we improve the diagnostic efficiency and predictive power of prodromal symptoms for schizophrenia?

• Published in: Schizophrenia research Vol. 42; no. 2; pp. 91 - 100
• Main Authors: McGorry, Patrick D., McKenzie, Dean, Jackson, Henry J., Waddell, Fiona, Curry, Christina
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 07-04-2000; Elsevier Science
• Subjects: Adolescent; Adult; Biological and medical sciences; Diagnostic efficiency; Duration; Female; Hospitalization; Humans; Male; Medical sciences; Middle Aged; Nosology. Terminology. Diagnostic criteria; Predictive Value of Tests; Predictors; Prodrome; Psychiatric Status Rating Scales; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychotic Disorders - diagnosis; Psychotic Disorders - etiology; QROC analysis; Schizophrenia; Schizophrenia - diagnosis; Schizophrenic Psychology; Sensitivity and Specificity; Techniques and methods; Schizophrenia; Prodrome; QROC analysis; Duration; Diagnostic efficiency; Predictors; Human; Prediction; Nosology; Revised drafting; Medical screening; Psychosis; Construct validity; Diagnostic and Statistical Manual III; Theoretical model; Criterion; Classification; Receiver operating characteristic curves; Critical study; Clinical investigation; Diagnosis; Inaugural sign; Signal detection; Prepsychotic state
• ISSN: 0920-9964; 1573-2509
• DOI: 10.1016/S0920-9964(99)00125-5

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.