目標：老年人屬多重藥物使用族群，且為藥物不良反應高危險群；雖然老年人潛在不適當用藥之問題，已受到全球醫療實務界之重視，但在台灣卻鮮少有相關研究。本研究目的為探討老年人潛在不適當用藥之影響因素，希望據此作為改善老年人處方用藥安全之參考。方法：本研究資料來源為國家衛生研究院「全民健康保險學術研究資料庫」之「承保抽樣歸人檔」(LHID2005)。並以「Beers老年人潛在不適當用藥準則-2002版」作為潛在不適當用藥之判斷標準，分析2005-2007年65歲以上老年慢性病患西醫門診處方潛在不適當用藥之影響因素，包括病患特性、醫療機構特性及醫師特性三大構面。結果：納入100,578位慢性病老人及其7,521,186張處方，其中91,772位慢性病老人(91.24%)至少接受過一次潛在不適當用藥，而其有1,839,654張處方(24.46%)為潛在不適當用藥；而病患性別、病患年齡、用藥品項數、醫療院所評鑑層級、就醫科別、權屬別、都市化程度、醫師性別、醫師年齡及醫師年資等，皆為處方潛在不適當用藥之影響因素。結論：國內老年人潛在不適當用藥之盛行率遠高於國外，衛生相關單位及醫師可參考本研究潛在不適當用藥影響因素之結果，謹慎處方以確保加強需要長期服藥的慢性病老年病患之健康及用藥安全。

Objectives: The elderly often receive poly-pharmacy and may be at a higher risk for adverse drug reactions. Potentially inappropriate prescribing in the elderly (PIPE) is one of the major patient safety concerns worldwide; however, few studies have been conducted on PIPE in Taiwan. The aim of this research was to investigate the risk factors associated with PIPE. Methods: The data source was the 2005-2007
Longitudinal Health Insurance Database (LHID2005), a nationally representative database established by the National Health Research Institutes. We analyzed the patients, facilities and physicians as risk factors for PIPE among patients over age 65 with chronic diseases. PIPE was identified by the 2002 Beers criteria. Results: A total of 91,772 patients (91.24%) out of 100,578 had received at least one PIPE between 2005 and 2007. Among a total of 7,521,186 outpatient prescriptions, 1,839,654 (24.46%) were PIPE. Patients’ gender, age, number of drug items, level of hospital, department visited, ownership, urbanization, and physician’s gender, age and seniority were the risk factors associated with PIPE. Conclusions: The prevalence of PIPE in Taiwan was higher than that in other countries. We suggest that health authorities and physicians consider the risk factors for PIPE in order to ensure drug safety for the elderly with chronic diseases.