Factors associated with initiation on clozapine and on other antipsychotics among medicaid enrollees

Objective: Demographic and clinical factors associated with starting clozapine and other antipsychotics were examined. Methods: New York State Medicaid claims from 2008 to 2009 identified individuals with a schizophrenia spectrum disorder, continuous Medicaid eligibility during the study, and at least one clinic service and antipsychotic fill. The sample included individuals who initiated an antipsychotic without any fills for the same medication in the prior 90 days (N=7,035). Results: Only 144 patients (2%) started on clozapine. They were more likely to be younger, white males who had received services in a state-operated facility, with more hospital admissions and higher total psychiatric costs. African Americans and Hispanics were less likely than whites to start on clozapine. Individuals with substance use disorders were less likely than those without them to start on clozapine. Conclusions: Clozapine was rarely prescribed, and problematic disparities were found. Quality improvement efforts are needed to ensure that patients are offered this effective treatment when appropriate.