Introduction: This study aimed to evaluate one-year real-world outcomes in patients with bipolar I disorder who were initiated on long-acting injectable (LAI) antipsychotics during hospitalization, focusing on hospitalization burden, treatment continuity, individual response heterogeneity, LAI persistence, and treatment simplification.
Methods: In this retrospective, single-center, mirror-image study, 48 patients were evaluated using clinical records from the year before and after LAI initiation. The primary outcome was the change in total hospitalization days. Secondary outcomes included the number of hospitalizations, readmissions, treatment continuity at ±3, ±6, and ±12 months, LAI maintenance, and medication changes. Paired pre- and post-LAI outcomes were analyzed using non-parametric tests.
Results: In patients with complete follow-up, the mean number of hospitalizations did not change significantly from the pre-LAI to post-LAI period (p=0.975), nor did the mean number of hospitalization days (p=0.885). Among patients with at least one pre-LAI hospitalization, the number of hospitalizations decreased from 1.29±0.72 to 0.71±0.85 (p=0.016). Treatment continuity increased from 68.8% to 95.8% between -3 and +3 months (p=0.001) and from 71.7% to 91.3% during the ±6-month period (p=0.022); however, no such increase was observed at ±12 months (82.1% vs. 84.6%; p=1.000). Individual hospitalization outcomes were heterogeneous, and 52.4% of patients with available data experienced a reduction in the number of medications during the follow-up.
Conclusion: Inpatient LAI initiation was associated with improved early treatment continuity but not with an overall reduction in one-year hospitalization burden. Because the index hospitalization was not a random time point, the observed pre- and post-differences cannot be attributed solely to LAI initiation.
Keywords: Bipolar disorder, long-acting injectable antipsychotics,