How expensive is antipsychotic polypharmacy?
Valuck RJ; Morrato EH; Dodd S; Oderda G; Haxby DG; Allen R; University of Colorado at Denver and Health Sciences Center, School of Pharmacy, Denver, CO 80262, USA. robert.valuck@uchsc.edu OBJECTIVE: To characterize healthcare costs associated with antipsychotic polypharmacy and to investigate predictors of high-cost patients. METHODS: A retrospective cohort study using Medicaid claims data from California, Nebraska, Oregon, Utah, and Wyoming evaluated 55 383 fee-for-service patients with antipsychotic prescriptions between 1998 and 2002. Polypharmacy was defined as initiating multiple antipsychotic drugs or concomitant antipsychotic therapy (>or=60 days). Healthcare costs (drug and non-drug) were summed for 365 days following index antipsychotic claim. Adjusted mean costs were compared to antipsychotic monotherapy. Logistic regression was performed to identify predictors of high-cost patients (top quintile) with regard to patient age, gender, race/ethnicity, mental disorders, hospitali
