Ethnicity and prescription patterns for haloperidol, risperidone, and olanzapine

Patients with schizophrenia may respond better to second-generation antipsychotics than to older antipsychotics because of their superior efficacy and safety profiles. However, the reduced likelihood among ethnic minority groups of receiving newer antipsychotics may be associated with reduced medication adherence and health service use, potentially contributing to poor response rates. This study examined whether ethnicity helped predict whether patients with schizophrenia were given a first- or a second-generation antipsychotic, haloperidol versus risperidone or olanzapine, and what type of second-generation antipsychotic was prescribed, risperidone or olanzapine, when other factors were controlled for.

Texas Medicaid claims were analyzed for persons aged 21 to 65 years with a diagnosis of schizophrenia or schizoaffective disorder who started treatment with olanzapine (N=1875), risperidone (N=982), or haloperidol (N= 726) between January 1, 1997 and August 31, 1998. The association between antipsychotic prescribing patterns among African Americans, Mexican Americans, and whites was assessed by using logistic regression analysis. Covariates included other patient demographic characteristics, region, comorbid mental health conditions, and medication and health care resource use in the 12 months before antipsychotic initiation.

The results of the first- versus second-generation antipsychotic analysis indicated that African Americans were significantly less likely than whites to receive risperidone or olanzapine. Although not statistically significant, the odds ratio indicated that Mexican Americans were also less likely to receive risperidone or olanzapine. Ethnicity was not associated with significant differences in the prescribing patterns of risperidone versus olanzapine.

When other factors were controlled for, African Americans were significantly less likely to receive the newer antipsychotics. Among those who received the newer antipsychotics, ethnicity did not affect medication choice.