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Atypical Antipsychotic Monotherapy for Schizophrenia: Clinical Review and Economic Evaluation of First Year of Treatment

Last updated: October 1, 2007
Issue: 91
Result type: Report

Technology and Condition

Widely available atypical antipsychotics (AAPs) (risperidone, olanzapine, quetiapine, and clozapine) for treatment of schizophrenia.

Issue

Prescription medication costs for schizophrenia – driven by the use of AAPs – increased from C$48.13 million in 1996 to C$150 million in 2004. Health funders and practitioners need to know the comparative costs and benefits of the four agents widely used for maintenance therapy of patients with schizophrenia.

Methods and Results

We appraised and summarized the findings from a drug class review on AAPs. A systematic review of economic evaluations was conducted, with a cost analysis from the perspective of a Canadian third-party payer. A deterministic decision tree followed a theoretical cohort of recently diagnosed and already-treated patients for 12 months, using observational data from a Canadian setting, and results from the clinical review. The model suggests that starting with risperidone, olanzapine, or quetiapine will cost the health system $17,939, $18,318, and $19,682 for the first 12 months respectively. Risperidone remained the least costly under different scenarios. Funding generic risperidone also represented the smallest fiscal impact to drug plan budgets.

Implications for Decision Making

  • Differences exist among atypical antipsychotics.
    The available evidence suggests that, compared with risperidone, olanzapine is associated with a lower risk of relapse and of treatment discontinuation, but is less well tolerated. Evidence also shows that clozapine use reduces suicide risk in high-risk patients, compared with olanzapine.
  • Costs to the health care system do not reflect differences in utilization costs. Generic and brand-name olanzapine will require a larger investment by drug plans than quetiapine and risperidone. These costs are offset by reduced downstream costs from hospitalization, the largest cost component for treating patients with schizophrenia.
  • Decisions should be revisited. The lack of high-quality evidence to inform first-line therapy reimbursement decisions suggests that additional analysis should be undertaken when comparative effectiveness studies are available. The costs associated with polytherapy, long-term treatment, and the role of traditional antipsychotics should be considered.

This summary is based on a comprehensive health technology assessment available from CADTH’s web site (www.cadth.ca): Farahati F, Boucher M, Moulton K, Williams R, Herrmann N, Silverman M, Skidmore B. Atypical antipsychotic monotherapy for schizophrenia: clinical review and economic evaluation of first year of treatment.