Identifying long-term patterns and predictors of concurrent psychotropic medicine use in residential aged care using group-based multi-trajectory modelling: the ‘MEDTRAC-Psychotropics’ longitudinal cohort study

Purpose: Psychotropic medicines are commonly used in residential aged care facilities (RACFs) despite notable safety concerns. No prior studies have examined the longitudinal concurrent use of psychotropic medicines. We aimed to identify trajectories of concurrent use of three psychotropic medication classes over time and determine predictors of trajectory group membership for residents with and without dementia.

Methods: A retrospective longitudinal cohort study including 30 RACFs in Sydney, Australia. The study participants included 2837 newly admitted permanent residents (n = 1344 with dementia) aged ≥ 65 years. We monitored weekly exposure to three psychotropic classes-antidepressants, antipsychotics, and anxiolytics/hypnotics-over three years. We used group-based multi-trajectory modelling to identify concurrent psychotropic medicine use.

Results: At baseline, 38.5%, 19.6%, and 16.7% of residents with dementia received antidepressants, antipsychotics, and anxiolytics/hypnotics, respectively, compared to 32.8%, 7.1%, and 16.5% in residents without dementia. The concurrent use of multiple psychotropic classes occurred in 23.3% of non-dementia and 31.6% of dementia cohorts. The model identified 6-group and 4-group trajectories as the optimal fit for dementia and non-dementia cohorts, respectively. Psychotropic use trajectories mostly remained stable over time in non-dementia cohorts, while dementia cohorts showed more diverse and fluctuating use. Multinomial logistic regressions identified eleven predictors of trajectory membership in dementia and nine in non-dementia cohorts.

Conclusion: One in three residents with dementia and one in five without dementia concurrently use multiple psychotropics often for extended periods, which may put residents at risk. Further research should assess the appropriateness of such use and consider strategies for improving health outcomes.