Polypharmacy among older adults with dementia compared with those without dementia in the United States

Abstract

Background/objectives: In older persons with dementia (PWD), extensive medication use is often unnecessary, discordant with goals of care, and possibly harmful. The objective of this study was to determine the prevalence and medication constituents of polypharmacy among older PWD attending outpatient visits in the United States.

Design: Cross-sectional analysis.

Setting and participants: PWD and persons without dementia (PWOD) aged ≥65 years attending outpatient visits recorded in the nationally representative National Ambulatory Medical Care Survey (NAMCS), 2014-2016.

Measurements: PWD were identified as those with a diagnosis of dementia on the NAMCS encounter form and/or those receiving an anti-dementia medication. Visits with PWD and PWOD were compared in terms of sociodemographic, practice/physician factors, comorbidities, and prescribing outcomes. Regression analyses examined the effect of dementia diagnosis on contributions by clinically relevant medication categories to polypharmacy (defined as being prescribed ≥5 prescription and/or nonprescription medications).

Results: The unweighted sample involved 918 visits for PWD and 26,543 visits for PWOD, representing 29.0 and 780 million outpatient visits. PWD had a median age of 81 and on average had 2.8 comorbidities other than dementia; 63% were female. The median number of medications in PWD was eight compared with three in PWOD (p < 0.001). After adjustment, PWD had significantly higher odds of being prescribed ≥5 medications (AOR 3.0; 95% CI: 2.1-4.3) or ≥10 medications (AOR 2.8; 95% CI: 2.0-4.2) compared with PWOD. The largest sources of medications among PWD were cardiovascular and central nervous system medications; usage from other categories was generally elevated in PWD compared with PWOD. PWD had higher odds of receiving at least one highly sedating or anticholinergic medication (AOR 2.5; 95% CI: 1.6-3.9).

Conclusion: In a representative sample of outpatient visits, polypharmacy was extremely common among PWD, driven by a wide array of medication categories. Addressing polypharmacy in PWD will require cross-cutting and multidisciplinary approaches.

Keywords: dementia; outpatient care; polypharmacy; prescribing.