Prevalence and impact of antipsychotic discontinuation among commercially-insured patients with bipolar disorder.

BACKGROUND

Antipsychotic discontinuation is common among patients with bipolar disorder, especially when psychotic symptoms are remitted. This analysis describes the prevalence, predictors, and economic impact of antipsychotic discontinuation among patients with bipolar disorder.

METHODS

A retrospective, observational study was conducted using administrative claims data in the IBM MarketScan Commercial Database. Patients with ≥1 claim with a diagnosis for bipolar disorder (manic or mixed) and newly-initiating antipsychotic therapy between 1 January 2011 and 30 June 2016 were included. Baseline characteristics were assessed in the 12 months prior to the initiation. Outcomes were assessed during a 24-month follow-up. Discontinuation of antipsychotic therapy was utilized as a predictor of healthcare costs in models adjusted for baseline characteristics. Using limited set of variables in the claims database, predictors of discontinuation were also assessed.

RESULTS

A total of 18,259 commercially-insured patients were identified as initiators of antipsychotics. Common comorbidities among the cohorts included major depressive disorder and dyslipidemia. Discontinuation was very common among these patients (85%). Major depressive disorder, drug abuse, and other substance abuse/dependency were predictive of discontinuation. Controlling for differences in baseline characteristics, discontinuation was associated with 33% higher inpatient and emergency visit costs (p <.001) among those using these services, and 24% higher total healthcare costs (p <.001) for the overall cohort.

CONCLUSIONS

Most patients with bipolar mania or mixed states discontinue antipsychotic treatment in less than 2 years. Antipsychotic discontinuation contributes to excess healthcare costs. Future research focusing on the reasons for discontinuation and tailoring disease management based on comorbidities may inform adherence improvement initiatives.