Abstract
BACKGROUND: Non-adherence to antipsychotic therapy among patients with schizophrenia is a key driver of relapse, which can lead to costly inpatient stays. Long-acting injectables (LAIs) may improve adherence, thus reducing hospitalizations, but inpatient cost reductions need to be balanced against higher drug acquisition costs of LAIs. Real-world evidence is needed to help quantify the economic value of oral atypical antipsychotics compared with LAIs. OBJECTIVE: The objective of this study was to compare healthcare costs and resource utilization between once-monthly paliperidone palmitate (PP) and oral antipsychotic therapy (OAT) in a population of Medicaid beneficiaries with schizophrenia. METHODS: A retrospective, observational study was performed using Truven Health MarketScan Medicaid claims data from 2009 to 2012. Marginal structural modeling, a form of weighted repeated measures analysis to control for differences between cohorts and time-varying confounding, was used to estimate monthly costs of care in 2012 US dollars and resource utilization over a 12-month period for patients in each cohort. RESULTS: While per-month mental-health prescription costs were US$1019 higher in the PP cohort, approximately 55 % of this premium was offset by lower inpatient and outpatient care costs, producing a mean monthly total cost differential of US$434 (95 % CI 298-569, p < 0.0001) for all-cause costs and US$463 (95 % CI 374-552, p < 0.0001) for mental-health-related costs. Use of PP also resulted in a 0.44 and 0.47 reduction in the odds of all-cause and mental-health-related hospitalizations and a 0.09 reduction in the odds of all-cause emergency department visits (p < 0.0001, p < 0.0001, and p = 0.0134, respectively) over the 12-month follow-up period. CONCLUSIONS: Treatment with long-acting injectable antipsychotics, such as PP, may reduce inpatient and outpatient healthcare services utilization and associated costs. These findings also suggest that patients with schizophrenia taking once-monthly PP may stand a lower risk of hospitalization than patients on OAT.