ORLANDO – Up to 39% of geriatric patients are taking potentially inappropriate medications, and this trend is associated with increased drug-related problems and health care costs, according to a recent study.
The findings should encourage physicians to be more critical in their prescribing decisions, said Diane M. Spokus, one of the authors of the study, which was presented as a poster at the annual meeting of the Gerontological Society of America.
The retrospective examination of medication use among 17, 971 managed-care patients aged 65 or older found that 6,875 (39%) were using at least one potentially inappropriate medication (PIM), including 13% who were using two or more PIMs.
PIMs were defined by the revised Beers criteria (Arch. Intern. Med. 2003;163:2716–24) as either “medications or medication classes that should generally be avoided in persons 65 years or older because they are either ineffective, or they pose unnecessarily high risk for older persons, and a safer alternative is available.”
The finding of a 39% rate of PIM prescriptions is higher than what has been previously reported, “but we attributed that to the fact that we included oral estrogen as a PIM, and that accounted for almost 10%,” Ms. Spokus said in an interview. After estrogen, the two most commonly prescribed PIMs were propoxyphene and combination products, as well as short-acting benzodiazepines (7% each), followed by digoxin (4.7%) and long-term, nonsteroidal anti-inflammatories (4.6%).
By using principal and secondary discharge diagnoses occurring within 30 days of the medication prescription, the study found a nearly threefold higher rate of drug-related problems among patients taking at least one PIM, compared with those not taking such medications (14% vs. 5%).
The most common drug-related problems were syncope (3.6%), malaise and fatigue (3.5%), dehydration (1.8%), sleep disturbances (1.5%), and any cognitive impairment (1.5%). PIMs were associated with increased costs, including facility-paid, provider-paid, and prescription costs (about $2,250 per patient over 6 months), compared with patients who were not taking the medications (about $1,000), with patients taking more than one PIM accounting for the highest costs.
A larger, prospective study is needed to determine which drugs are associated with the most problems, Ms. Spokus said. The researchers also noted that their measures were limited in their ability to infer causality–something that might be achieved in a prospective study.