The effect of early initiation of aripiprazole once-monthly 400 mg on health care resource utilization and health care costs in patients diagnosed with bipolar I disorder: Real-world evidence from US claims data.

Abstract

Bipolar I disorder (BP-I) is a chronic and recurrent mental health disorder, broadly characterized by patients who alternate between the extremes of the mood spectrum: mania or hypomania; and depression. In 2015, the total estimated annual cost of BP-I in the United States reached more than $200 billion, approximately 2.5 times higher than the general population, largely driven by the increased use of acute health care services. Long-acting injectable antipsychotics such as aripiprazole were developed to significantly reduce patient burden for treatment adherence compared with oral formulations, to allow consistent dosing and improved outcomes. Previous real-world evidence studies have shown the benefits of starting aripiprazole once-monthly injection (AOM) at an early stage in patients diagnosed with schizophrenia; however, the effect of early initiation in the BP-I population remains unknown. To evaluate the impact of initiating AOM 400 mg (AOM 400) in adults at an early stage (<180 days) following a diagnosis of BP-I compared with late initiation (>365 days) in a real-world setting, via a retrospective analysis using claims data from the MarketScan Medicaid database. Study outcomes included the numbers of emergency department, hospitalization, outpatient, and pharmacy visits, together with the associated costs over a 1-year time horizon. A generalized linear model was used to compare the annualized costs associated with early, intermediate, and late initiators of treatment, using late initiators as the main reference group. Among 866 patients diagnosed with BP-I (median age, 36 years), 161 early initiators had significantly lower risks of emergency department visits (incidence rate ratio = 0.76; 95% CI, 0.61-0.94) and outpatient pharmacy visits (incidence rate ratio = 0.82; 95% CI, 0.73-0.93) compared with 591 late initiators. Early initiators also incurred lower pharmacy visit costs ($18,787 vs $23,503; <i>P</i> = 0.03) and lower medical costs ($13,898 vs $18,277; <i>P</i> = 0.01). Overall, early initiators incurred much lower total health care costs than late initiators during the follow-up ($31,086 vs $40,599, respectively; <i>P</i> < 0.001). Early initiators also incurred significantly lower total health care costs than intermediate initiators ($31,086 vs $40,892; <i>P</i> = 0.01). This real-world study demonstrates that early initiation of AOM 400 among patients living with BP-I may offer a significant advantage of lower health care resource utilization and associated costs when compared with late initiation.