Prevalence of central nervous system-active polypharmacy in a cohort of older adults in Argentina

Abstract

Background Central nervous system (CNS)-active polypharmacy is frequent and potentially harmful in older patients. Data on its burden outside the USA and European countries remain limited. Aims To estimate the period prevalence of and factors associated with out-of-hospital CNS-active polypharmacy in older adults. Method We used data from a cohort of out-patients aged ≥60 years affiliated to the Hospital Italiano de Buenos Aires’ health maintenance organisation on 1 January 2021. A CNS-active polypharmacy event was defined as the concurrent exposure to ≥3 CNS-active medications (i.e. antidepressants, anti-epileptics, antipsychotics, benzodiazepines, Z-drugs and opioids) through filled out-of-hospital prescriptions. We calculated the period prevalence of CNS-active polypharmacy for 2021. We identified factors associated with CNS-active polypharmacy using a multivariable logistic regression model to estimate odds ratios and 95% confidence intervals (CI). Results We included 63 857 patients. Pre-existing mental health diagnoses included anxiety (21%), depressive (14%) and sleep (11%) disorders. CNS-active polypharmacy occurred in 4535 patients, for a period prevalence of 7.1% (95% CI: 6.9–7.3%). The combination of an antidepressant, an antipsychotic and a benzodiazepine accounted for 21% of the CNS-active polypharmacy events. Frontotemporal dementia (odds ratio: 14.67; 95% CI: 4.47–48.20), schizophrenia (odds ratio: 7.93; 95% CI: 4.64–13.56), bipolar disorder (odds ratio: 7.20; 95% CI: 5.45–9.50) and depressive disorder (odds ratio: 3.50; 95% CI: 3.26–3.75) were associated with CNS-active polypharmacy. Conclusions One in 14 adults aged 60 years and older presented out-of-hospital CNS-active polypharmacy. Future studies should evaluate measures to reduce CNS-active medication use in this population.