Health care resource utilization and costs of California Medicaid patients with schizophrenia treated with paliperidone palmitate once monthly or atypical oral antipsychotic treatment

Objective: To compare all-cause health care utilization and costs between patients with schizophrenia treated with once monthly paliperidone palmitate (PP1M; Invega Sustenna(1)) and atypical oral antipsychotic therapy (OAT). Methods: This was a retrospective claims-based analysis among adult California Medicaid (Medi-Cal) patients with schizophrenia having 2 claims for PP1M or OAT from 1 July 2009 to 31 December 2013 and continuous health plan enrollment for 1 year pre- and post-index date (PP1M or OAT initiation date). Baseline characteristics were reported descriptively. Propensity score matching with a 1:1 greedy match method was used to create two matched cohorts. Treatment patterns, all-cause health care utilization, and costs for the 12 month follow-up period were compared between the two matched cohorts. Results: Two well matched cohorts of 722 patients were produced with similar baseline characteristics. During the 12 month follow-up period, PP1M patients were significantly less likely to discontinue treatment (30.6% vs. 39.5%, p<.001) or switch to a new therapy (21.6% vs. 27.7%, p=.007). PP1M patients had fewer inpatient visits (5.0 vs. 7.9, p<.001), lower mean hospitalization days (15.0 vs. 27.7 days, p<.001) and inpatient costs ($5060 vs. $10,880, p<.001). While pharmacy costs were significantly higher in the PP1M cohort ($16,347 vs. $9115, p<.001), total costs were not significantly different between the matched cohorts ($25,546 vs. $25,307, p=0.853). Conclusions: Patients with schizophrenia treated with PP1M had significantly fewer inpatient hospitalizations and associated costs with no significant difference in the total costs between the two cohorts. This study is subject to limitations associated with claims data such as miscoding, inability to examine clinical severity, etc.