The Impact of Olanzapine, Risperidone, or Haloperidol on the Cost of Schizophrenia Care in a Medicaid Population

Abstract Objective The objective of this study was to assess the impact of medication treatment on Medicaid costs for persons with schizophrenia. Methods Michigan Medicaid claims from January 1995 through  September 1998 were analyzed for  persons with schizophrenia diagnoses who initiated olanzapine ( n = 458), risperidone ( n = 481), or haloperidol ( n = 252) treatment between January 1996 and September 1997. Total and component Medicaid payments were compared for the year after treatment initiation, with simultaneous adjustment for patient demographics, comorbid conditions, prior medication use, prior service use, and prior year costs. Results Significant baseline differences existed between the groups in prior medication and service use. Adherence to index medication varied between the groups ( O = 60%; R = 54%; H=37%; P P = .002) and haloperidol (–$2,080, P = .003), whereas the risperidone and haloperidol groups were not significantly different. The differences were driven by significantly lower cost for inpatient services for other medications among the olanzapine group. Conclusion Total costs of schizophrenia care associated with olanzapine, risperidone, or haloperidol were similar, but  component costs differed. Relative to risperidone or haloperidol, olanzapine may have a higher acquisition cost, but may decrease inpatient costs and be associated with more optimal medication use patterns. Use of risperidone may also increase pharmacy costs and be associated with greater persistence, relative to haloperidol.