Real-World Effectiveness of Long-Acting Injectable and Oral Antipsychotic Agents in US Medicare Patients with Schizophrenia

Introduction

Daily oral antipsychotics (OAPs) are the mainstay of schizophrenia treatment; however, long-acting injectable antipsychotics (LAIs) are associated with better treatment adherence and improved outcomes.

Methods

This study assessed the real-world comparative effectiveness of LAIs and daily OAPs using claims data from a nationally representative sample of fee-for-service Medicare beneficiaries with schizophrenia. Antipsychotic discontinuation, psychiatric hospitalization, and treatment failure were compared relative to different reference groups using within-individual Cox regression models.

Results

The study included 152,835 patients (mean age, 53.5 years; 54.0% male and 61.5% white). LAIs when grouped by dosing intervals were associated with significantly lower risk of antipsychotic discontinuation (hazard ratios [HRs] 0.27–0.69), psychiatric hospitalization (HRs 0.76–0.88), and treatment failure (HRs 0.55–0.74) compared with OAPs. When LAIs of different dosing intervals and OAPs were broken out by type of agent and compared with oral risperidone, second-generation LAIs, specifically LAI paliperidone (every 3 months [Q3M] and monthly [Q1M]), LAI aripiprazole (Q1M), and LAI risperidone (primarily every 2 weeks), had a significantly lower risk of antipsychotic discontinuation (HRs 0.19–0.67), psychiatric hospitalization (HRs 0.76–0.91), and treatment failure (HRs 0.53–0.85). Second-generation LAI paliperidone (Q3M) had the lowest risk for negative outcomes relative to OAPs; this effect was maintained when the reference group was changed to oral risperidone, LAI risperidone, LAI aripiprazole (Q1M), and LAI haloperidol (Q1M) (33–47% lower risk).

Conclusion

Efforts are needed to enhance identification of appropriate candidates for LAIs and increase their uptake, especially longer dosing interval LAIs, in the Medicare population.