More than a third of older adults are prescribed potentially inappropriate drugs, study finds

We know that medication overload— multiple medication use that causes harm–is prevalent among older Americans. Nearly two-thirds of older Americans take five or more medications (including over-the-counter drugs and supplements), putting them at greater risk for adverse drug events and hospitalizations. A new study on potentially inappropriate medications (PIMs) further demonstrates the risks of overprescribing for older Americans, and sheds light on prescribing trends in this population.

In a recent study in the Journal of the American Geriatrics Society, researchers from the University of Buffalo looked at a sample of 218 million older adults in the 2011–2015 Medical Expenditure Panel Survey (MEPS). They found that within those five years, over 34% of older adults were prescribed at least one potentially inappropriate medication (PIM). The researchers used the 2019 Beers Criteria to identify drugs that were inappropriate for older adults. Some of the most commonly prescribed potentially inappropriate medications they found were benzodiazepines, sedative hypnotics, skeletal muscle relaxants, and first generation (sedative) antihistamines.

Older adults taking five or more medications were much more likely to have been prescribed a PIM. Among the full patient sample, 57% of people were taking five or more medications and 43% were prescribed fewer than five. In the group that received at least one PIM, 82% were taking five or more medications and 18% were taking fewer than five.

The authors noted several other traits associated with PIMs. Women, white people, people with lower education levels, people with lower incomes, people on public health insurance (in addition to Medicare), people in the Midwest and South, and people with worse reported mental health were all at increased risk of PIMs. Chronic health conditions such as heart disease, diabetes, and hypertension were also associated with greater risk of PIMs.

“There are certainly other factors that play into the likelihood of patients being prescribed a PIM, particularly patient’s access to care,” said Dr. Collin M. Clark, Clinical Assistant Professor at the School of Pharmacy and Pharmaceutical Sciences at the University of Buffalo, and one of the study authors. “Do patients have prescription insurance coverage? Do they have a regular provider that is responsible for their care? Do they see a geriatrician, a primary care provider, or some other medical specialist? These are areas I think need more investigation” he said.

In the study, PIMs were associated with greater health care utilization (potentially due to adverse drug events) and higher costs of care. The authors found that older adults prescribed a PIM were more likely to go to the emergency room (26% more likely) or to be hospitalized (17% more likely) compared to those were not prescribed a PIM, adjusting for other patient characteristics. Older adults prescribed a PIM also spent more than those without a PIM on prescription drugs ($128 more) and spent more in total health care costs ($458 more), even controlling for chronic conditions and other patient factors.

There was some good news: From 2011 to 2015, the rate of PIMs for older adults declined slightly. In 2011, 35.3% of people were prescribed a PIM, while 32.5% were prescribed a PIM in 2015. Prescriptions of certain potentially harmful medications including antidepressants, muscle relaxants, digoxin, and non-benzodiazepine hypnotics also decreased over this time.

However, the authors noted that prescriptions of some harmful medications commonly targeted for deprescribing in older adults (such as anti-cholinergic drugs, benzodiazepines, and proton pump inhibitors) did not decrease over this time period. “Many of these classes of medications take more effort by clinicians and patients to deprescribe in practice,” said Clark. “More research is needed to better understand the best approaches to deprescribing these medications and assessing the clinical impact of such interventions.”