A pharmacoeconomic model of outpatient antipsychotic therapy in "revolving door" schizophrenic patients

Abstract

Background: The discrepancy between supply and demand in health care today requires that psychiatrists and other providers of patient care expand their traditional role from one of patient advocate to one of allocator of care. In this new role, the care provider must consider not only the efficacy and safety of a therapeutic regimen, but also its impact on society in terms of quality of life and cost-effectiveness.

Method: A variety of pharmacoeconomic analysis methodologies have been used to assess the economic and quality of life consequences of alternate treatment strategies. A clinical decision analysis model that takes into account compliance rates and associated rehospitalization was used to compare the direct treatment costs associated with alternate outpatient neuroleptic strategies for "revolving door" schizophrenic patients. The antipsychotic treatment options considered were traditional oral neuroleptics (e.g., haloperidol), depot neuroleptics (e.g., haloperidol decanoate), and "atypical" oral agents (e.g., risperidone).

Results: The results of this decision analysis model (based on a set of reasonable outcome probabilities and costs) suggest that, under five sets of cost and outcome assumptions, switching to the depot route in a patient with a history of relapse and rehospitalization may reduce total direct treatment costs by approximately $650 to $2600/year compared with an atypical agent and approximately $460 to $1150/year compared with a traditional oral neuroleptic. Under a sixth set of assumptions-namely, a compliance rate with atypical oral drug (80%) equal to that with the depot agent and an average wholesale price of the atypical drug 25% lower than current wholesale price-the atypical oral drug treatment option would be approximately $700 less than treatment with a depot agent, and $1860 less than treatment with a traditional neuroleptic.

Conclusion: The decision analysis model presented here indicates that, under a variety of assumptions, switching a revolving door patient to a depot medication for outpatient maintenance therapy could result in lower total direct treatment costs over the first year. This finding was consistent, although to varying degrees, under differing probability and cost assumptions. The proposed model can be used in other clinical circumstances, such as treatment-refractory patients or those with severe negative symptoms, as well as with other associated outcome probabilities and costs. Application of this model in different clinical scenarios associated with different outcome probabilities and treatment costs, however, may well provide different results.