Impact of Paliperidone Palmitate versus Oral Atypical Antipsychotics on Healthcare Resource Use and Costs in Veterans with Schizophrenia and Comorbid Substance Abuse
This poster was presented at the 29th Annual U.S. Psychiatric & Mental Health Congress, held October 21-24, 2016, in San Antonio, Texas.
Background: Data on treatment of schizophrenia with paliperidone palmitate (PP) among patients with comorbid substance abuse (SA) are limited.
Objective: Compare all-cause and SA-specific healthcare resource utilization (HRU) and costs in veterans with schizophrenia and co-occurring SA treated with PP versus oral atypical antipsychotics (OAA).
Methods: Veterans Health Administration electronic health record data were used to conduct a retrospective longitudinal study in veterans with schizophrenia who initiated PP or OAA between 1/1/10-6/30/15, had ≥12 months of enrollment prior to treatment initiation (baseline), were diagnosed with SA, and had ≥1 Global Assessment of Functioning score during baseline. Differences in baseline characteristics were adjusted for using inverse probability of treatment weighting. Adjusted cost differences (CD) and incidence rate ratios (IRR) for the association between PP versus OAA and all-cause and SA-specific healthcare costs and HRU in the 12 months following treatment initiation were estimated using weighted regression models.
Results: Of 6,872 veterans in the study, 1,684 (25%) and 5,188 (75%) were treated with PP and OAA, respectively. After adjustment, PP was associated with fewer all-cause inpatient (IRR=0.88), mental health-related inpatient (IRR=0.88), and long-term care stays (IRR=0.53), but more frequent mental health intensive case management visits (IRR=1.51) compared to OAA (all p<0.001). IRRs were even lower for SA-specific HRU. Relative to OAA, PP was also associated with lower average annual all-cause (CD=-$10,473, p<0.001) and SA-specific (CD=-$8,457, p<0.001) medical costs.
Conclusion: PP was associated with significant total medical cost savings resulting from fewer hospitalizations compared to OAA in patients with schizophrenia and SA.