OBJECTIVES: This study examined disease burden before and after initiation of LAIs in commercially insured young adults with schizophrenia.

METHODS: This retrospective observational cohort study used IBM MarketScan Commercial Claims and Encounters Database, 1/1/2008-12/31/2019. Patients with ≥1 inpatient or ≥2 outpatient claims with schizophrenia diagnosis were identified; date of first diagnosis was index date. Patients were aged 18-35 years at index date, with continuous enrollment ≥1-year baseline and ≥1-year follow-up, with ≥1 LAI during follow-up. A pre-post analysis was conducted with paired t-tests to compare relapse (defined as hospitalization or emergency department visit), healthcare resource utilization, and costs before (from index date to LAI initiation) and after LAI initiation (to end of follow-up). Outcomes were reported as Per-Patient-Per-Month (PPPM).

RESULTS: We identified 2222 patients who initiated LAIs after index date (mean age=22.9, 70.4% male), with 1421 (64.0%) initiating LAIs after post-index oral antipsychotic treatment. Remaining 36.0% initiated LAIs as index treatment. Average time from index date to LAI initiation was 433.1 days (median 243), and from LAI initiation to end of follow up was 744.0 days (median 630). PPPM relapse event rate was 0.109 before LAI initiation, and 0.073 after LAI initiation (p<0.0001). All-cause direct medical costs (excluding medication), medication costs, and total costs were $4587, $311, and $4898 PPPM before and $2535, $542, and $3078 PPPM after LAI initiation, respectively. All these cost numbers were statistically significantly different (P<0.0001) from before to after LAI initiation.

CONCLUSIONS: In commercially insured young adults with schizophrenia, use of LAIs was associated with decreased relapse event rate vs the period before LAI initiation. Although medication costs increased in the post LAI period, the cost increase was more than offset by the decreased costs associated with total care. This study demonstrated that LAI treatment for young adults with schizophrenia is associated with significant cost savings to commercial payers.