Long‐Term Trend of Polypharmacy in Older People in Taiwan From 2000 to 2013

Polypharmacy in older adults is associated with risk of multiple negative health consequences, including poor physical and cognitive function, potentially inappropriate medications, and adverse drug events.1-5 Most studies report the prevalence of polypharmacy only of the year studied. For example, it was reported that the prevalence of polypharmacy (≥ 5 prescribed drugs) was approximately 37% in older people in Germany in 2017.6 The long-term trend of polypharmacy in older people has not been reported. Longitudinal data can reveal the severity of polypharmacy; long-term follow-up is needed to provide such kind of data. To explore this, an observational study was designed to examine the database of the Taiwan National Health Insurance Program from 2000 to 2013, which has information on 23 million people living in Taiwan.7, 8 Individuals aged 65 and older were included. Polypharmacy was defined as taking an average of 5 or more prescribed drugs per day. In 2000 and in 2013, approximately 0.1% of older people did not take prescribed drugs (Figure 1). Seventy-seven percent were taking 1 to 4 prescribed drugs daily in 2000 and 67.8% in 2013, 20% were taking 5 to 9 prescribed drugs daily in 2000 and 26.3% in 2013, and 2.9% were taking 10 or more prescribed drugs daily in 2000 and 5.8% in 2013. Therefore, the prevalence rates of polypharmacy were 22.9% in 2000 and 32.1% in 2013. The prevalence of polypharmacy seemed to be increasing annually. Individuals aged 65 and older accounted for 8.6% of the total population in Taiwan in 2000 and 11.5% in 2013.9 The aging population was increasing in Taiwan annually. In our observational study, the prevalence rates of polypharmacy also increased from 2000 to 2013 (from 22.9% to 32.1%). We observed that there was a positive association between the increasing trend of aging population and the increasing prevalence of polypharmacy in Taiwan. That is, as the aging population increases, the prevalence of polypharmacy also increases. In Western countries, the increasing trend of aging population is a challenge. Although no formal data are available, we speculate that the prevalence of polypharmacy in older people is also increasing annually in Western countries. We also observed that more than 99% of older people took at least 1 prescribed drug every day from 2000 to 2013, which raises new questions. Do older people really need to take drugs every day? Do older people have a potential to reduce unnecessary drugs? Because polypharmacy has been found to be associated with negative health outcomes in older people, strategies to reduce unnecessary drugs should be used to decrease polypharmacy and improve the quality of care of older people. The study was conducted in accordance with the Declaration of Helsinki. The research ethics committee of China Medical University and Hospital in Taiwan (CMUH-104-REC2-115) approved this study. Informed written consent was waived because the study was a retrospective analysis of data. Financial Disclosure: This study was supported in part by the Ministry of Health and Welfare, Taiwan (MOHW107-TDU-B-212-123004) and China Medical University Hospital in Taiwan (DMR-107-192).