(280) An economic model assessing costs, relapses, and antipsychotic adherence of switching Medicaid beneficiaries with schizophrenia from oral antipsychotics to once-monthly, once-every-three-months, and once-every-six-months paliperidone palmitate

Background: : Among patients with schizophrenia, nonadherence to oral antipsychotics (OAPs) increases the risk of relapse, leading to a substantial economic burden.

Objective: : To evaluate the plan-level impact on healthcare costs, relapse rates, and average antipsychotic (AP) adherence of switching Medicaid beneficiaries with schizophrenia from OAPs to once-monthly paliperidone palmitate (PP1M) alone, and with subsequent transitions to once-every-three-months (PP3M) and once-every-six-months paliperidone palmitate (PP6M).

Methods: : A 36-month Markov model with 3-month cycles was developed from a Medicaid payer perspective. Three cohorts of adults were included: those treated with once- or twice-daily OAPs, those switching to PP1M only, and those switching to PP1M with on-label transitions to PP3M and PP6M. At each 3-month cycle, patients may or may not be adherent to AP treatment, may or may not experience a relapse, and could continue receiving the same treatment or switch treatments. Literature-based model inputs included treatment-specific relapse and adherence rates. Outcomes reported by cohort comprised plan-level healthcare costs, relapses, and average AP adherence.

Results: : In a hypothetical health plan of 1 million Medicaid beneficiaries, an estimated 13,419 adult members with schizophrenia treated with OAPs incurred plan-level costs of $1,253.5 million, based on 33,671 relapses and average AP adherence of 69.5%. Switching 20% of patients from OAPs to PP1M only (n=2,684), plan-level costs were $1,147.3 million, 29,322 relapses were observed, and average AP adherence among switchers was 76.9%, translating to plan-level cost savings of $106.2 million, 4,349 avoided relapses, and an increase in AP adherence of 7.4%. Incorporating transitions to PP3M and PP6M, plan-level costs were $1,137.4 million, 28,672 relapses were observed, and average AP adherence among switchers was 85.4%, representing plan-level cost savings of $116.1 million, 4,999 avoided relapses, and an improvement in AP adherence of 15.9% compared to patients treated with OAPs. Relative to patients treated with PP1M only, incorporating transitions to PP3M and PP6M resulted in plan-level cost savings of $9.9 million, 650 avoided relapses, and an increase in AP adherence of 8.5%.

Conclusions: : Switching Medicaid beneficiaries with schizophrenia from OAPs to PP1M resulted in substantial plan-level cost savings, driven by reduced relapse rates and increased AP adherence. Incremental cost savings, further reductions in relapse rates, and continued adherence improvements were observed when incorporating transitions to PP3M and PP6M.

Sponsorship:: Johnson & Johnson