Ethnicity effects on clinical diagnoses compared to best-estimate research diagnoses in patients with psychosis: A retrospective medical chart review

Objective: Ethnicity effects on diagnoses are frequently reported and have variably been attributed to diagnostic biases versus ethnic differences in environmental exposures, and other factors. Method: We compared best-estimate gold standard research diagnoses to clinical diagnoses (DSM-III-R and DSM-IV criteria) among 129 white, 57 African American, and 50 Hispanic patients with psychosis admitted to an inpatient research unit from 1990 to 2003. Results: Clinical and research diagnoses showed greater agreement in Hispanic than in African American patients (white patients were intermediate). Diagnostic agreement for paranoid schizophrenia was likewise the best in Hispanic patients. While paranoid schizophrenia tended to be overdiagnosed in African American patients, it was underdiagnosed in white patients. Patterns of diagnostic agreement for schizoaffective disorder and other diagnoses were similar among the 3 ethnic groups. Conclusions: Diagnostic unreliability may explain the excess of paranoid schizophrenia reported for African Americans. Further research is needed to elucidate the influence of ethnicity on clinical diagnosis before other theories to explain group differences can be reasonably proposed and reliably tested.