Background: Healthcare costs for schizophrenia patients differ across pharmacotherapies, with possible implications for state healthcare policy formulation. Objective: To compare the costs and healthcare utilization of Medicaid patients with schizophrenia prescribed atypical antipsychotics (AA): aripiprazole, risperidone, quetiapine, olanzapine, or ziprasidone. Methods: This retrospective cohort analysis used medical and pharmacy claims data from 24 state Medicaid plans. The study sample comprised of all single-eligible patients 18-64 years with schizophrenia who initiated new AA therapy from 2001-2007. Patients were followed for 6 months before and 12 months after their first AA prescription. Generalized linear models in an Intent-to-Treat (ITT) framework compared outcomes across AAs while controlling for baseline demographics, comorbidities, and disease severity. Aripiprazole was the reference drug for all comparisons. Results: In the follow-up period, hospitalizations occurred in 31.8% of the sample (n=254,619) and annual inpatient costs averaged $6,188. Patients initiating treatment with aripiprazole had significantly lower rates of hospitalization (26.8%) versus quetiapine (36.7%), risperidone (32.6%), and ziprasidone (32.1%), but not olanzapine (24.9%). Adjusted inpatient costs were significantly lower for aripiprazole ($4,537) versus quetiapine ($7,281), risperidone ($6,510), and ziprasidone ($5,536), but not olanzapine ($5,078). Unadjusted total annual medical costs averaged $17,849. Adjusted costs for patients on aripiprazole ($15,688) were significantly lower than olanzapine ($16,398) and quetiapine ($16,685), but not risperidone ($15,610) or ziprasidone ($15,984). Conclusions: Among Medicaid schizophrenia patients newly treated with AAs, aripiprazole had lower hospitalization rates and costs versus patients receiving other AAs except olanzapine. Lower total medical costs were also observed for aripiprazole versus olanzapine and quetiapine.
Dana Goldman, PhD; Iftekhar Kalsekar, PhD; Kimberly Laubmeier, PhD
Bristol-Myers Squibb and Otsuka Pharmaceutical Co., Ltd.