PMH26: OUTPATIENT ANTIPSYCHOTIC USE: COMPARING ATYPICAL AND CONVENTIONAL ANTIPSYCHOTIC ADHERENCE USING A NATIONAL RETAIL PHARMACY DATA BASE

Abstract

OBJECTIVES: We report on trends in medication adherence for patients who received conventional and atypical antipsychotics under routine outpatient care during a 9-month period in 1998–9. METHODS: Refill records were analyzed for over 25,000 patients at a national retail pharmacy chain. Persistence was defined as a patient's possession of medication at 30 day intervals from a patient's initial prescription. Persistence was taken as a proxy for medication adherence. RESULTS: The percentage of patients adhering to therapy at nine months was 44.4% for atypical agents; 47.6% for conventional agents; and 71.1% for clozapine. CONCLUSIONS: Improved clozapine adherence was associated with a closely supervised medication administration process that ensured patient tracking and frequent and sustained patient-provider contact. Atypical agents, with their improved side-effect profile relative to conventional agents, were not associated with better adherence. These results suggest that improved side-effect profiles alone may not insure higher levels of medication adherence and that improved medication administration processes may facilitate higher levels of outpatient medication adherence for patients with major mental illness.