Risk factors of potentially inappropriate medications among older patients visiting the community health center in rural Taiwan

The adverse drug reactions caused by potentially inappropriate medications (PIMs) are closely related to emergency department visits and acute hospital admissions in the elderly population. It has been reported that 11.5-14% of community-dwelling elderly patients were prescribed for at least one PIM, but little is known regarding to it in rural Taiwan. The purpose of this study was to evaluate the prevalence and risk factors of PIMs among older patients visiting the outpatient clinic of a community health center in rural Taiwan. In August of 2008, all elderly patients attended the outpatient clinic of a community health center in I-Lan County were enrolled for study. PIMs are evaluated by Beers' criteria. In total, 327 patients (mean age: 74.8 ± 5.3 years old, 49.5% males) were enrolled, and 27.5% (90/327) of them were prescribed for at least one PIM. The most common PIMs were antihistamines (50.9%) and muscle relaxants (39.0%). In particular, 87.6% of these PIMs were having a high severity potential. Patients had PIMs were significantly older (76.2 ± 6.9 vs. 74.2 ± 6.1 years, p= 0.011), being prescribed for more drugs (3.7 ± 1.4 vs. 2.4 ± 1.7 items, p< 0.001), and more commonly to visit due to acute diseases (64.4% vs. 24.9%, p< 0.001) than those had no PIM. Multiple logistic regression showed that older age (OR = 1.05, 95% CI = 1.00-1.09, p= 0.046), higher number of prescribed medications (OR = 1.66, 95% CI = 1.39-1.98, p< 0.001), and diagnosis of acute diseases (OR = 8.98, 95% CI = 4.71-17.10, p< 0.001) are all independent risk factors for PIMs. In conclusion, the prevalence of PIMs in the outpatient clinic of the community health care center in rural Taiwan was 27.5%. Older age, higher number of prescribed medications and diagnosis of acute diseases are independent risk factors for PIMs in rural Taiwan.