The predictive validity of a diagnosis of schizophrenia. A report from the International Study of Schizophrenia (ISoS) coordinated by the World Health Organization and the Department of Psychiatry, University of Nottingham

TY - JOUR

T1 - The predictive validity of a diagnosis of schizophrenia.

T2 - A report from the International Study of Schizophrenia (ISoS) coordinated by the World Health Organization and the Department of Psychiatry, University of Nottingham

AU - Mason, Peter

AU - Harrison, Glynn

AU - Croudace, Tim

AU - Glazebrook, Cristine

AU - Medley, Ian

N1 - M1 - Article

PY - 1997/4/1

Y1 - 1997/4/1

N2 - Background Outcome is important in the validation of psychiatric diagnosis, as most disorders lack clinicopathological correlates. We describe the predictive validity of four definitions of schizophrenia (DSM-III-R, ICD-10, ICD-9 and CATEGO S+), in a representative cohort of patients selected during their first episode of psychosis. Method Each definition of schizophrenia was applied to 99 patients. Their respective ability to predict 13-year outcome (Global Assessment of Functioning scales) was assessed. Results DSM-III-R and ICD-10 diagnoses of schizophrenia have high predictive validity for long-term outcome, and both provide relatively stable diagnoses. ICD-9 is reasonably good at predicting disability, but not symptoms, and CATEGO S+ showed no predictive validity. Adding six-month duration criteria to ICD-10, ICD-9 and CATEGO S+ improved their predictive validity, and removing the six-month duration criterion from DSM-III-R commensurately reduced predictive validity. Conclusions Modern diagnostic systems (DSM-III-R and ICD-10) have high predictive validity, and are superior to ICD-9. The six-month duration criterion of DSM-III-R schizophrenia accounts for its predictive validity and stability over 13 years, but restricts its use in first-episode studies. The one-month duration criterion of ICD-10 is less restrictive, without major compromises in predictive validity or stability.

AB - Background Outcome is important in the validation of psychiatric diagnosis, as most disorders lack clinicopathological correlates. We describe the predictive validity of four definitions of schizophrenia (DSM-III-R, ICD-10, ICD-9 and CATEGO S+), in a representative cohort of patients selected during their first episode of psychosis. Method Each definition of schizophrenia was applied to 99 patients. Their respective ability to predict 13-year outcome (Global Assessment of Functioning scales) was assessed. Results DSM-III-R and ICD-10 diagnoses of schizophrenia have high predictive validity for long-term outcome, and both provide relatively stable diagnoses. ICD-9 is reasonably good at predicting disability, but not symptoms, and CATEGO S+ showed no predictive validity. Adding six-month duration criteria to ICD-10, ICD-9 and CATEGO S+ improved their predictive validity, and removing the six-month duration criterion from DSM-III-R commensurately reduced predictive validity. Conclusions Modern diagnostic systems (DSM-III-R and ICD-10) have high predictive validity, and are superior to ICD-9. The six-month duration criterion of DSM-III-R schizophrenia accounts for its predictive validity and stability over 13 years, but restricts its use in first-episode studies. The one-month duration criterion of ICD-10 is less restrictive, without major compromises in predictive validity or stability.

U2 - 10.1192/bjp.170.4.321

DO - 10.1192/bjp.170.4.321

M3 - Article

SN - 0007-1250

VL - 170

SP - 321

EP - 327

JO - British Journal of Psychiatry

JF - British Journal of Psychiatry

IS - 4

ER -