Potentially Inappropriate Medication Use in Older Adults With Multimorbidity in Taiwan

Medication-related problem is a concerning issue in older adults with multimorbidity due to complexity of disease conditions and polypharmacy, and may lead to increase in risk for adverse health outcomes. This study aims to investigate the prevalence and associated factors of potentially inappropriate medication use among the growing population of older adults with multimorbidity in Taiwan.

The study population was composed of patients who were aged 65 years or older with multimorbidity (two or more chronic diseases) and had at least one outpatient clinic visit with drug prescription in 2018 identified from the Taiwan National Health Insurance Research Database. Potentially inappropriate medication use was defined using the 2019 Beers criteria for drugs to be avoided for older adults. Multiple logistic regression model was conducted to examine patient-related and prescriber-related factors associated with PIM use.

A total of 2 432 416 patients (69.7% of the entire older adult population) had multimorbidity and received at least one drug prescription at the outpatient clinic in Taiwan in 2018. The prevalence of having at least one PIM in this population was found to be 85.6%. Patient-related factors (age, sex, specific chronic diseases, frequency of outpatient visits) and prescriber-related factors (physician characteristics, healthcare setting, total number of medications, prior PIM use) were found to be associated with use of PIM.

High prevalence of PIM use was found in older patients with multimorbidity in Taiwan. Both patient-related and prescriber-related factors had been found to be predictors of PIM use, and should be addressed when trying to improve the medication quality in this population.