目標：非計劃性重返急診是病患照護警訊，本研究藉由探討病患72小時內重返急診因子， 作為改善重返急診現況之依據。方法：合併某醫院2019年病患72小時內重返急診回溯性資料及2020年7月結構式問卷收集急診醫師資料，依病患是否重返急診，以年齡、性別及身份別經傾向分數予1：2配對，並以卡方及t檢定、邏輯式迴歸進行72小時內重返急診風險因子分析。結果：2019年急診病患返診率4.47%，病患性別、檢傷分類、就診時間、急診壅塞程度、醫師年齡及年資對於病患72小時內重返急診之影響不顯著；病患年齡、身分別(重大傷病)、離院方式、急診滯留時間(6-48小時)、醫師人格特質(神經質)與工作疲勞顯著影響是否重返急診。結論：針對影響病患72小時重返急診之病人、醫院相關風險因子，建議將年老者、重大傷病身份、自行離院、自動出院患者列為衛生教育的重點族群，提前加強出院衛教與溝通；而醫師因素部分可藉由改善醫師人力調派、提供緩解工作疲勞的措施或政策來減輕醫師工作疲勞程度。

Objectives: Unexpected revisits to the emergency department (ED) may indicate poor patient care and quality issue. This study investigated factors related to unexpected revisit to the ED within 72 hours of discharge. Methods: This study retrospectively analyzed patient data from an ED system in 2019. Additionally, a structured questionnaire was designed to collect data on physicians’ personality and work fatigue. The combined data were matched by age, sex, and type of insurance cover by using propensity score matching with a ratio of 1:2. The risk factors of unexpected return to the ED within 72 hours were evaluated using the chi-square test, independent t-test, and logistic regression. Results: Of the 91,582 included patients, 4,086 patients returned, yielding an unexpected revisit rate of 4.47%. The results found that patients’ sex, triage level, arrival shift, ED crowding, physician age, and seniority were not significant indicators of ED revisits within 72 hours. Patients’ age, type of insurance cover (severe illness), mode of leaving, a length of stay in the ED (6-48 hours), and the physician’s neuroticism and work fatigue were significant predictors of ED revisit. Conclusions: For patient and hospital related factors, patients with advanced age, severe disease, and those likely to leave without notice or against advice should be prioritized for outpatient education. For physician related factors, reforms to reduce the workload of physicians are essential. Further studies should continue to identify risk factors for hospitals to effectively reduce unexpected revisits to the ED within 72 hours.