Prevalence and determinants of potentially inappropriate medications in elderly inpatients in Thailand: a retrospective observational study based on the 2019 Beers criteria.

Background: The prevalence of potentially inappropriate medications (PIMs), including NSAIDs, first-generation antihistamines, tricyclic antidepressants (TCAs), and benzodiazepines among elderly inpatients in Thailand, based on the 2019 Beers criteria, is insufficiently investigated.

Methods: This study retrospectively examined 300 elderly patients in a Thai tertiary hospital, assessing four PIM classes based on the 2019 Beers criteria and exploring factors and variations in PIM prescription patterns across different phases of hospitalisation.

Results: The study found an overall PIM prescription rate of 28%, consisting of: benzodiazepines (14%), first-generation antihistamines (9%), NSAIDs (3%), and TCAs (2%). Patients taking at least 5 medications prior to admission were more likely to receive PIMs (OR 3.77, 95% CI 1.15-12.35). Furthermore, PIM prescription was significantly associated with age, showing a 4.8% yearly increase (p = 0.01), and the number of comorbidities increased by 16.2% per unit (p = 0.021). Additionally, PIM use during admission was significantly linked to a longer hospital stay (OR 3.32, 95% CI 1.50-7.33).

Conclusions: These findings emphasise the need for continued monitoring and optimisation of medication management, and collaboration between pharmacists and physicians to review and adjust prescriptions, especially in elderly inpatients experiencing polypharmacy and multiple comorbidities.