[[alternative]]The effect of organizational ecology changes of medical institutions for the district hospital survival in comparisons of different area characteristics

[[abstract]]背景與目的醫院所處區域的組織生態變化是影響一家醫院存續的重要指標。醫療生態結構變化是一個長期的動態過程，不同時期的變化情形可能會有不同的影響，若以橫斷面的角度探討無法窺得不同區域環境的動態性趨勢。據此，本研究加入時間變動的觀察角度，探討我國全民健保實施下，區域醫療組織生態變化對我國地區醫院存續之影響。研究方法本研究分析單位以醫院為基礎，使用1996~2011年全民健康保險研究資料庫100萬抽樣歸人檔為本研究之分析資料，篩選出臺灣地區2002年至2011年之地區醫院為本研究對象，追蹤其10年期間存續狀況；依據組織生態理論之觀點，結合Cox迴歸及時間相依變量分析技術，探討不同區域特質下，地區醫院自身條件與隨時間變動因子對地區醫院存續之影響。研究結果我國地區醫院家數自2002年至2011年期間呈現減少的趨勢。公立醫院或有學校經營之私立醫院存活機率較其他權屬別高，私立醫院則最低。南區業務組累積生存函數較其他業務組為低，台北業務組累積生存函數則較高。透過結合時間相依因子之存活分析結果發現，不同層級醫院密度會影響地區醫院的存續狀況，其中區域的機構密度差異與統合性人口特質會產生不同的交互影響。位處於高層級醫療機構密集的區域，地區醫院存續狀況會受到高層級醫療機構變動的影響。而處於人口密度高或老化指數較高的區域，地區醫院存續狀況仍受到醫學中心與區域醫院家數變動之影響。但是位處於人口密度低、平均每戶醫療保健支出較少區域，地區醫院存續則受到同樣為地區醫院之家數變動影響。相對而言，診所家數之長期更迭對地區醫院之存續情況則較無相關。結論本研究結合組織生態理論，提出我國不同區域特質下，機構間動態變化對地區醫院存續之影響實證分析。加入時間變化的風險因子有助於探討地區醫院之存續影響，並更能完整呈現整個臺灣醫療市場的生態結構變化。[[abstract]]Background and objects Changes in the diversity of organizational forms affect the district hospital survival. It has been regarded that the evolution of medical organizational ecology refers to long-term changes rather than a cross-sectional viewpoint and may have different impacts in varying stage. Therefore, the current study is aimed to explore the relationship between medical organizational ecology changes and district hospital survival within a given set of time-varying variables under the National Health Insurance.Research methods This study is a hospital-based retrospective cohort study. Data used in this study were retrieved from the National Health Insurance Research Database provided by the Department of Health at Bureau of National Health Insurance. All district hospitals located in Taiwan from 2002 to 2011 were selected as the analytic targets and their 10-yr long-term development were further studied based on the organizational ecology theory. Research results Our data show that the number of district hospitals was decline in Taiwan from 2002 to 2011. The district hospitals with government or private school ownership had higher survival rate than others. In regard to regional divisions, southern division had lower survival rate than others. After controlling for the time-varying factors in survival analysis, it was found that different levels of hospital density will affect district hospital survival. Besides, there are significant interactions between institution density and population demography in different areas. For those district hospitals located in area with high-level hospitals network, high population density and high aging propensity, the high-level hospitals network significantly affect the district hospital survival. By contrast, district hospitals could compete with each other for survival and majority in area with characteristics of low population density and average family expenditure in health. Furthermore, the distribution density of clinics seems to be unrelated to district hospital survival.Conclusions and recommendations This study provides observed area heterogeneity in district hospitals survival and explicitly addresses differences in power relations between district hospital survival and their area characteristic sequence of density change in hospital environment competition. From the angle of organizational ecology point of view, including time-dependent variables is helpful to understand the district hospitals survival in today's turbulent health care delivery environment in Taiwan. Keywords: district hospital survival, survival analysis, organizational ecology theory, time-varying factor