Changes in diagnosis in a 9-year national longitudinal sample.

Studied are changes in diagnosis in a random sample of 10% of all first admissions to psychiatric hospitals and psychiatric wards of general hospitals in Israel from 1983 to 1990 with follow-up evaluation to 1991. This included 4,570 hospitalizations of 2,220 patients. Data were extracted from the National Psychiatric Case Registry of the Ministry of Health. Almost 59% of the sample had one admission, 18% had two, 9% had three, and 14% had four or more. From the first admission to the last discharge (a mean of 2.15 years), 59.2% of the patients' diagnoses did not change. In 89.46% of the cases in which the diagnosis changed, the changes took place during the first admission. Diagnostic change differed between diagnostic groups. In descending order of stability in diagnosis from the first admission to the last discharge were neurotic and personality disorder (73.6%), mental retardation (73.5%), schizophrenia (73.0%), organic conditions (70.6%), affective disorders (66.2%), substance abuse (65.6%), childhood disorders (60%), paranoid disorder (43.6%), other nonorganic psychosis (30.3%), and V-codes (25.0%). The average level of diagnostic agreement between the first admission and the last discharge was a kappa of .52. The average length of stay for patients whose diagnosis became more severe was considerably longer than for patients whose diagnosis became less severe or did not change in level of severity. Older age was related to less change in diagnosis. For patients aged less than 18 years, diagnosis changed in 46.7% of the cases, for patients aged 19 to 44, 31.2%, and for patients older than 45, 27.8%.