An investigation of psychoactive polypharmacy and related gender-differences in older adults with dementia: A retrospective cohort study

Abstract

Background: Older adults with dementia may express challenging responsive behaviours. One management strategy is pharmacologic treatment though these options have limited benefit. The limited benefit may lead to multiple treatments being prescribed. Methods: The aim of the present study was to describe psychoactive medication polypharmacy and explore factors associated with psychoactive polypharmacy in a cohort of older adults with dementia in Nova Scotia, Canada, including a gender-stratified analysis. This was a retrospective cohort study of those aged 65 years or older with a recorded diagnosis of dementia between 2005 and 2015. Medication dispensation data was collected from April 1, 2010, or dementia diagnosis (cohort entry) to either death or March 31, 2015 (cohort exit). Psychoactive medication claims were captured. Psychoactive medication polypharmacy was defined as presence of three or more psychoactive prescription medications dispensed to one subject and overlapping for more than 30 days. Psychoactive polypharmacy episodes were described in duration, quantity, and implicated medications. Regression analysis examined factors associated with experience and frequency of psychoactive polypharmacy. All analysis were stratified by gender. Results: The cohort included 15,819 adults with dementia (mean age 80.7 years; 70.0% female), with 54.3% (n = 15,728) receiving at least one psychoactive medication. 19.3% met the definition of psychoactive polypharmacy. Logistic regression adjusted for age at dementia diagnosis, year of dementia diagnosis, and rural or urban location of residence demonstrated for both men and women that younger age was associated with increased risk of psychoactive polypharmacy (women: OR 0.97, 95%CI[0.96, 0.98], men: OR 0.96, 95%CI[0.95, 0.97]). Men were less likely to experience psychoactive polypharmacy if their location of residence was urban (OR 0.86, 95%CI[0.74, 0.99]), but there was no significant association between location of residence (urban or rural) and polypharmacy for older women with dementia. Antidepressants were the most dispensed class, while quetiapine was the most dispensed medication. Conclusions: This study suggests that younger adults with dementia are dispensed more psychoactive medications and that adults with dementia living in rural locations may benefit from increased access to non-pharmacological options for dementia management.