Time to rehospitalization in patients with bipolar mania discharged on long-acting injectable or oral antipsychotics

Abstract

Objective: This study aimed to analyze time to rehospitalization in patients with bipolar mania discharged on long-acting injectable antipsychotics (LAIs) or oral antipsychotics (OAPs). Additionally, temporal trends in LAI prescription were investigated.

Methods: Patients with bipolar mania discharged from the study hospital on antipsychotics between 2006 and 2018 were included. Survival analysis was used to compare time to rehospitalization within one year of discharge between patients discharged on LAIs and OAPs, and between FGA-LAIs (first- generation antipsychotic) and SGA-LAIs (second-generation antipsychotic). The Cochrane-Armitage trend test was used to test whether a temporal trend existed for LAI prescription rates during the study period.

Results: The LAI group (n = 224) had a significantly lower rehospitalization rate and a significantly longer time to rehospitalization than the OAP group (n = 3836). Rehospitalization rate and time to rehospitalization were not significantly different between patients discharged on FGA-LAIs or SGA-LAIs. The LAI prescription rate grew significantly from 2.20% in 2006 to 11.58% in 2018 (Z = 5.5843, p < 0.0001). The prescription rate of SGA-LAIs also increased significantly (Z = 7.7141, p < 0.0001), but not the prescription rate of FGA-LAIs.

Limitations: The treatment allocation is not randomized in this retrospective study. Furthermore, various clinical characteristics were unavailable in our analysis, such as symptom severity, functional impairment, and others.

Conclusions: LAIs were significantly superior to OAPs in reducing rehospitalization risk. However, SGA-LAIs were comparable with FGA-LAIs in reducing rehospitalization risk. Use of LAIs increased significantly in discharged patients with bipolar disorder during the study period, especially SGA-LAIs.

Keywords: Adherence; Bipolar mania; Long-acting injectable antipsychotics; Mood stabilizers; Rehospitalization.