目的：探討病患、醫師及醫療機構相關特性與急診病患三天內重返急診的關係。方法：本研究使用國家衛生研究院發行之全民健康保險研究資料庫2000年百萬人歸人檔之資料，使用邏輯斯迴歸（logistic regression）探討影響急診病患三天內重返急診的相關因素，以SAS9.4統計套裝軟體進行資料整理與統計分析。結果：研究對象共計89,708位使用過急診的病患，其中4,860人（5.42%）三天內重返急診；2,879人（3.21%）因相同疾病診斷三天內重返急診，其中有1,160人（40.29%）重返不同醫院急診。男性病患、19歲以上病患、循環系統病患、消化系統病患、檢傷分類為第一、二、三級病患、區域及地區醫院病患、低度都市化病患、非公立醫院病患、低收入戶病患重返急診的機率較高。結論：影響急診病患三天內重返急診的相關因素為病患性別、病患年齡層別、疾病診斷類別、檢傷分類級數、投保地區都市化程度及機構層級別。相同疾病類別三天內重返急診者，有40.29%至不同的醫院急診，這種現象的原因值得進一步探討。

Objectives: We analyzed the relationship between return visits to the emergency department (ED) within three days and various characteristics associated with patients, physicians and medical institutions. Methods: The longitudinal health insurance database of one million subjects randomly selected from all beneficiaries in 2000. All ED visits in 2013 were analyzed for return visits to the ED within three days. A multivariate logistic regression analysis was utilized to evaluate the independent effect of various characteristics of return visits to the ED within three days. Results: The overall rate of return visits to the ED within three days was 5.42% (4,860/89,708). The overall rate of return visits to the ED with the same diagnosis category within three days was 3.21% (2,897/89,708). Of these 2,897 return visits, 1,160 (40.29%) returned to the ED of a different hospital. Being male, aged ＞=19, ED visits within a diagnostic category of endocrine system or circulatory system, ED visits to regional hospitals or district hospitals, ED visits with triage acuity scales one, two, or three, subjects living in areas with a low level of urbanization, subjects on welfare, and ED visits to non-public hospitals independently increased the risk of return visits to the ED within three days. Conclusions: The risk of return visits to the ED within three days was associated with demographic characteristics, diagnosis at the initial ED visit, accreditation level of the hospital, and triage acuity scale. We noted that a large proportion (40.29%) of patients with the same diagnosis category made return visits to a different hospital. The reasons for this phenomenon warrant further investigation.