OBJECTIVES : Long acting injectables (LAIs) were developed in part to combat low adherence in schizophrenia. This study examines clinical and healthcare service use in schizophrenia patients switching to LAI antipsychotics.

METHODS : Adults who received a LAI (index date) between January 1, 2013 and October 31, 2018 were selected from the IBM MarketScan^® Commercial Claims and Encounters Database. Patients were continuously eligible for 6-months prior to and 3-months following index, had ≥1 inpatient or ≥2 outpatient claims with a schizophrenia diagnosis, and ≥56 days’ supply of oral antipsychotics the pre-period (6-months pre-index). Clinical characteristics were described in the pre-period; service use and costs were compared pre- to post-LAI switch.

RESULTS : The study included 1,001 schizophrenia patients (mean age: 37.04 years; 63% male); the most common LAIs were haloperidol (21%), risperidone (18%), and aripiprazole (15%). Prior to switch, the most used oral antipsychotics were risperidone (39%), quetiapine (25%), and olanzapine (24%), with an average of 167.7±104.9 days’ supply; 19% used ≥3 different oral antipsychotics. Comorbid psychiatric conditions included schizoaffective (44%), generalized anxiety (31%), and drug use (29%) disorders. Concomitant pre-period medications included antidepressants, medications impacting nerve conduction, and anticonvulsants. Per-person-per-month (PPPM) all-cause and schizophrenia-related visits in the inpatient (0.21±0.23 to 0.09±0.20; 0.11±0.14 to 0.04±0.14) and emergency (0.26±.041 to 0.17±0.44; 0.08±0.18 to 0.06±0.24) settings decreased, while office visits (0.70±0.74 to 0.92±0.95; 0.21±0.36 to 0.38±0.64) increased following switch, ps<0.05. PPPM all-cause ($4,726±$5,161 to $3,567±$5,280) and schizophrenia-related ($2,894±$3,933 to $2,210±$3,889) costs decreased approximately 24% following switch, ps<0.001.

CONCLUSIONS : Switching to LAI was associated with an increase in outpatient visits but a decrease in inpatient and emergency visits. Overall, this alteration in service utilization led to reduced healthcare costs following LAI switch. Although LAI formulations may not be appropriate for all patients, this study suggests they can effectively manage disease and contain costs in particular cases.