Prevalence and Risk Factors for Psychotropic Medication Use in Older Adults in Australia: A Nationwide Data Linkage Study.

Background and objectives: Psychotropic medications are associated with an increased risk of adverse drug events in older adults, yet national data on their use in Australia remain limited. This study aims to estimate the prevalence of psychotropic medication use among older Australians and to examine the sociodemographic factors associated with their use.

Methods: A retrospective cross-sectional study was conducted using national linked data from the 2021 Census and the Pharmaceutical Benefits Scheme (PBS). The study included all individuals aged 65+ years who responded to the 2021 Census and received at least one PBS medication between 1 August and 31 October 2021. Prevalence of psychotropic medication use was calculated across 5-year age groups, and sociodemographic factors associated with each psychotropic subclass were assessed by logistic regression model.

Results: Among the 3,850,281 older adults, 31.1% received at least one psychotropic medication. Prevalence increased with age across all subclasses except antiepileptics. Antidepressants were the most commonly used psychotropics (19.9%). Those needing assistance with core activities (odds ratio, OR 2.05, 95% confidence intervals, CI 2.03-2.06) and living in non-private dwellings (OR 2.02, 95% CI 1.99-2.05) were more likely to receive psychotropics. Conversely, higher educational level, socioeconomic status and non-English speaker were associated with a lower use of all psychotropic subclasses. Aboriginal and Torres Strait Islander people were linked to increased use of benzodiazepines (OR, 1.15; 95% CI 1.10-1.20) and opioids (OR, 1.20; 95% CI 1.16-1.23). Dementia was strongly associated with antipsychotic (OR, 2.59; 95% CI 2.52-2.66) and antidepressant (OR, 1.42; 95% CI 1.40-1.44) use. Arthritis significantly increased the likelihood of opioid use (OR, 2.03; 95% CI 2.02-2.05).

Conclusions: Almost one third of the study population used psychotropic medications between August and October 2021. Aboriginal and Torres Strait Islander people, individuals with dementia and those with arthritis had an increased likelihood of using certain psychotropic medications. Future research should evaluate the clinical appropriateness of psychotropics in these populations, with immediate implementation of strategies to ensure that their use is limited to evidence-based indications.