Are there patients with late-onset schizophrenia in state hospitals?

Diagnoses of all individuals admitted between 1989 and 1991 to a State of Illinois Hospital were examined to determine the prevalence of patients meeting DSM-III-R criteria for late-onset schizophrenia. Four prevalence rates were determined for each year based on the frequency of late-onset patients in (1) total psychiatric admissions, (2) total admissions over age 45, (3) admissions with diagnoses of schizophrenia, and (4) admissions over age 45 and diagnosed schizophrenia. Results showed that the mean (across the three years) of the four prevalence rates of late-onset schizophrenia ranged from 0.24% to 4.1%. This range is far below prevalence rates on hospitalized patients previously reported in the literature (6 to 34%). Reasons for discrepancy are discussed.