Patterns, determinants, and outcomes of early use of antidementia drugs: A 6-year multicenter cohort study in Thailand.

Background: Evidence on antidementia drugs (ADD) use in developing countries, where accessibility to ADD is challenging, is limited. Our aim was to examine prescribing patterns, factors, and outcomes associated with the early-ADD use (within 3 months from diagnosis) in people with dementia.

Methods: A retrospective cohort study included individuals aged ≥ 60 years with dementia from three hospitals in Thailand between 2015 and 2020. Participants were categorized as non-ADD users, early-ADD users, and delayed users. ADD switching and one-year persistence were analyzed. Multivariable logistic regression was used to identify factors associated with early-ADD prescribing and its impact on clinical outcomes, including in-hospital death and hospitalization.

Results: 3,116 patients were included. The ADD prescription rate was 14.31 %, with 79.82 % of those being early-ADD users. Donepezil was the most prescribed (70.18 %). The one-year persistence rate of any ADD was 24.89 %. Factors associated with early-ADD use included the Civil Servant Medical Benefit Scheme, dyslipidemia, and dementia type. Early-ADD use was associated with reduced in-hospital death (adjusted odds ratio [aOR]=0.46, 95 % CI: 0.22-0.96, p = 0.038) and hospitalization (adjusted OR = 0.70 95 % CI: 0.51-0.97, p = 0.034) after controlling for age, sex, and Charlson Comorbidity Index.

Conclusion: ADD prescription rates were relatively low, with a one-year persistence rate of 25 %. Early-ADD use may improve clinical outcomes by reducing hospitalization and in-hospital mortality. These findings provide clinical features of ADD used in real-world settings and highlight the need for adherence to practice standards and strategies to promote ADD persistence among individuals with dementia.