Polypharmacy linked to negative health outcomes in older adults with Alzheimer's

Polypharmacy, commonly defined as taking five or more medications daily, is a significant health care concern impacting over 30% of older adults. It is associated with poor health outcomes like falls, medication interactions, hospitalizations and even death. Older adults are at an increased risk of experiencing polypharmacy if they have multiple chronic conditions. While older adults with Alzheimer's disease and related dementias are more likely to be taking more than five medications, there is little research examining the impact of multiple daily medications on symptoms, health outcomes and physical function in older adults with Alzheimer's disease and related dementias.

Researchers from Drexel University's College of Nursing and Health Professions recently published a study in Biological Research For Nursing examining symptoms, health outcomes and physical function over time in older adults with and without Alzheimer's disease and related dementias and polypharmacy.

Led by Martha Coates, PhD, a postdoctoral research fellow in the College, the research team found that individuals who experiencing polypharmacy and have Alzheimer's disease and related dementias experience more symptoms, falls, hospitalizations, mortality and had lower physical function – indicating that polypharmacy can also negatively impact quality of life for older adults with Alzheimer's disease and related dementias.

The cut-off of point of five or more medications daily has been associated with adverse health outcomes in previous research, and as the number of medications increase the risk of adverse drug events and harm increases."

Martha Coates, PhD, postdoctoral research fellow, Drexel University's College of Nursing and Health Professions

The research team used a publicly available dataset from the National Health and Aging Trends Study – a nationally representative sample of Medicare beneficiaries in the United States from Johns Hopkins University. Since 2011, data is collected yearly to examine social, physical, technological and functional domains that are important in aging.

For this study, the research team used data from 2016 through 2019 to compare changes in symptoms, health outcomes and physical function among four groups: 1) those with Alzheimer's disease and related dementias and polypharmacy; 2) those with Alzheimer's disease and related dementias only; 3) those with polypharmacy only; and 4) those without either Alzheimer's disease and related dementias or polypharmacy.

Coates explained that the researchers used analytic weights to analyze the data, which generates national estimates, making the sample of 2,052 individuals representative of 12 million Medicare beneficiaries in the U.S., increasing the generalizability of the findings.

"We found that older adults with Alzheimer's disease and related dementias and polypharmacy experienced more unpleasant symptoms, increased odds of falling, being hospitalized and mortality compared to those without Alzheimer's disease and related dementias and polypharmacy," said Coates. "They also experienced more functional decline, required more assistance with activities of daily living like eating, bathing and dressing, and were more likely to need an assistive device like a cane or walker."

Coates noted that there are tools available to help health care providers review and manage medication regimens for older adults experiencing polypharmacy and possibly taking medications that are potentially inappropriate or no longer provide benefit. However, currently there are no specific tools like that for older adults with Alzheimer's disease and related dementias.

The findings from this research shed light on the negative impact polypharmacy can have on older adults with Alzheimer's disease and related dementias. But Coates added that further research is needed to develop strategies to reduce the occurrence of polypharmacy in people with Alzheimer's disease and related dementias.

"The older adult population is growing in the U.S., with an estimated 80 million individuals over the age of 65 by 2040," said Coates. "This means that the number of older adults diagnosed with Alzheimer's disease and related dementias will also increase, and currently there is no cure. Avoiding adverse outcomes related to polypharmacy can improve quality of life and prevent excess disability for older adults with Alzheimer's disease and related dementias."

The research team anticipates this study will help guide future analysis of the impact of specific medications on health outcomes in individuals with Alzheimer's disease and related dementias and that it provides a foundation to support intervention development for medication optimization in older adults with Alzheimer's disease and related dementias and polypharmacy.