Assessment of Changes in Utilization of Health-Care Services After Implementation of a Prior Authorization Policy for Atypical Antipsychotic Agents

BACKGROUND: In 2004, the Georgia Medicaid program implemented a prior authorization (PA) policy for certain atypical antipsychotic agents, resulting in an average savings of $2.7 million per year. OBJECTIVE: To determine whether implementation of a PA policy for atypical antipsychotic drugs increased health-care utilization in the Georgia Medicaid program from July 2003 to April 2006. METHODS: A single cohort observational study employing segmented regression and time series analysis was conducted to determine health-care services utilization, including emergency department (ED) visits, outpatient office visits, hospital admissions, and length of stay (LOS). Study subjects included continuously eligible adult Georgia Medicaid recipients with a schizophrenia-related diagnosis and documented use of an atypical antipsychotic medication (N = 12,120). Where applicable, analysis of a noncontinuously eligible population was also performed to investigate disenrollment bias in study results. RESULTS: A significant decline in post-policy trend for the average number of ED visits (absolute difference -0.042 per member per month (PMPM); relative difference -20.92%) and average number of hospital admissions PMPM (absolute difference -0.010 PMPM; relative difference -22.27%) was observed at the end of the study period. Baseline and pre-policy trends were found to be significant predictors for both endpoints. Significant models were not identified for average outpatient office visits PMPM or average LOS per admission. CONCLUSIONS: In contrast to other published studies on PA for atypical antipsychotics, patient outcomes improved after the initiation of the policy. To the extent that medical utilization reflects patient health outcomes and health status, the results of this study indicate that the PA program has potentially improved the health of schizophrenic patients in Georgia and lowered program costs.