A Group-based Trajectory Analysis of Longitudinal Psychotropic Agent Use and Adverse Outcomes Among Older People

Objective: Existing evidence on long-term psychotropic polypharmacy in older people is scarce despite serious safety concerns regarding this issue. This study aims to identify distinct trajectories of longitudinal psychotropic agent use and to examine the association with the risk of mortality and unplanned hospitalization according to distinct trajectories. Design: A retrospective longitudinal cohort study based on data from Taiwan's National Health Insurance Research Database (NHIRD). Setting and participants: A population-based study including 39,803 eligible participants aged 65 years or older who were newly prescribed oral psychotropic agents in 2004. Measures: We assessed 5 years of monthly consumption of psychotropic agents among eligible participants and used group-based trajectory modeling to identify distinct groups of longitudinal psychotropic use. Cox proportional hazards models were used to examine the association between distinct trajectories of longitudinal psychotropic agent use and subsequent 1- and 3-year unplanned hospitalization and all-cause mortality. Results: Among 39,803 eligible participants, we identified 5 trajectories of longitudinal psychotropic agent use over a 5-year follow-up period: sustained intense (7.1%), moderate increasing (12.1%), decreasing (13.4%), slowly increasing (15.7%), and infrequent users (51.6%). Moderate increasing and sustained intense use were associated with significantly higher risks of unplanned hospitalization [moderate increasing use: hazard ratio [HR] 1.30, 95% confidence interval (CI) 1.18-1.44; sustained intense use: HR 1.40, 95% CI 1.24-1.58] and all-cause mortality (moderate increasing use: HR 1.25, 95% CI 1.09-1.44; sustained intense use: HR 1.32, 95% CI 1.12-1.56) than infrequent use. Similar results were observed at 3 years of follow-up. Conclusions/Implications: Older people with moderately increasing and sustained intense use of psychotropic agents over time had higher risks of unplanned hospitalization and mortality. Tracking older people's use of psychotropic agents over time may help to identify individuals at greatest risk of unplanned hospitalization and mortality.