城鄉差距與可避免住院之相關性研究

Abstract

研究背景： 台灣有許多針對城鄉差距的健康研究，其測量指標的劃分依不同研究者、研究目的而各有不同的定義，例如：平均餘命、嬰兒死亡率或是特定疾病的死亡率等。然而城鄉差距到生命的死亡是一段很長的距離，影響個人的死亡因素有許多，單以平均餘命表示城鄉差距，其敏感性似乎是不足的，而單以特定疾病來測量城鄉差距其所回答的題目或答案可能也有所受限。美國醫學研究所(institute of medicine,IOM) 1993年的報告指出可避免住院(或稱因門診照護敏感疾病而住院)是衡量基層醫療的良好指標，其概念為獲得良好且適當的門診照護或得到即時且有效的醫療照護，以降低不必要的住院風險。本研究欲更進一步分析台灣城鄉間是否存在可避免住院風險的差異。 研究目的： 探討台灣居住在不同都市化程度的鄉鎮市區居民，其可避免住院風險是否有所不同，並進一步釐清醫療可近性在城鄉和可避免住院間是否扮演中介變項的角色。 研究方法： 本研究為橫斷性研究，利用國家衛生研究院全民健康保險資料庫，以2005年一百萬承保抽樣歸人檔之2010年健保資料進行分析。本研究以18歲以上且於2010年在保之中央健康保險署納保人為研究對象，再以被保險人投保地、呼吸道感染門診就醫地、被保險人身分、投保類別與被保險人年齡相互搭配估計被保險人之居住地。排除無法估計其居住地的被保險人後，並排除住院天數超過三個標準差的離群值個案，共568,641人。本研究參考謝雨生等學者的鄉鎮市區數位發展分類研究報告，依鄉鎮市區其都市化程度的不同，分成高、中、低三組，控制性別、年齡、共病、門診次數以及社經地位，分析都市化程度與可避免住院之間的相關性。此外，為釐清醫療可近性是否為城鄉與可避免住院的中介變項，本研究根據Baron & Kenny所提出的「迴歸法」來檢定醫療可近性是否為中介因子 (Reuben M. Baron & Kenny, 1986)。 研究結果： 研究對象568,641人中，2010年因門診照護敏感疾病而住院的有9,230人，占所有人口的1.62%。都市化程度高、中以及低的可避免住院人次占率分別為14.62%、16.19% 以及17.36%。多變項邏輯斯迴歸分析顯示，都市化程度越高的地區其可避免住院風險越低，且達統計學上顯著相關(P<0.0001)。此外，研究結果也發現醫療可近性為城鄉與可避免住院的部分中介因子。 結論： 本研究發現城鄉間的可避免住院率確有不同，且醫療可近性是城鄉與可避免住院的部分中介因子。

Abstract Background: There are many reports concerning the urban-rural differences in health care. The indicators used include life expectancy, infant mortality rate, and mortality rate of specific disease. However, life expectancy is not sensitive enough to reveal the urban-rural gap in health care. Besides, there are limitations in using mortality rates for specific diseases to explain the differences. In 1993, Institute of Medicine in the United States reported that “Hospitalization for Ambulatory Care Sensitivity Conditions” is a good indicator to monitor access to health care services. The key concept of ambulatory care sensitive conditions (ACSCs) is ‘‘for which good outpatient care can potentially prevent the need for hospitalization or for which early intervention can prevent complications or more severe disease‘‘. This study aims to analyze the health care differences between urban and rural areas using hospitalization for ACSCs as a measure for health outcome in Taiwan. Purpose: To examine the association between the urbanization and hospitalization for ACSCs, and further investigate whether the access to health care services is the mediator between ACSC hospitalizations and urbanization. Materials and methods: This is a cross-sectional study. All data is from the academic database of National Health Insurance (NHI) in National Health Research Institute. We analyzed the one million ebrollees data on the year of 2010, who has been enrolleed in 2005.The study included those were 18 years and older in 2010. Using methods suggested by previous researchers, we tried to identify the residantal area for each of the NHI enrollees in our study by using insurance classification, location of clinic/hospital visit, and insurance registration information, and we excluded those enrollees whose residence could not be identified. A total of 568,641 persons were included in the analysis. We divided the sample into three groups by the level of urbanization, and adjusting for sex, age, comorbidity, the number of physician visits and socioeconomic status variables in the models. Besides, we use the Statistical Mediation Analysis (Baron& Kenny) to examine whether access to health care is a mediator between the urban-rural gap and hospitalization for ACSCs. Results: Among the 586,641 subjects, there were 9230 persons admitted with ACSCs.The rates of ACSC hospitalization were 14.62%, 16.19%, and 17.36% by the level of urbanization from high to low level. According to the multiple logistic regression modles, the higher the level of urbanization the lower the rates of ACSC hospitalization (P<0.0001). Besides, we found that access to health care was a partial mediator between the urbanization and hospitalization for ACSCs. Conclusion : Our study found that the rates of hospitalization for ACSCs differs between the urban and rural areas, and the accessibility to primary care is a partial mediator of this association.