目的：檢視醫師人口比值的高低對有保險者西醫門診利用率的影響。方法：以有保險者為分析對象，採用兩部分模式(two-part model)進行分析，將醫療次區域中每萬人口醫師數分為高、中、低三組，檢視醫師數的高低對西醫門診利用的影響。有關個人門診利用與基本資料的來源，為1994年臺灣地區國民保健調查資料，有關居住地區的醫師人口比資料來源，為1994年行政院衛生署的醫事人員現況調查與內政部編印的臺閩地區人口統計。結果：控制了其它相關影響變項後，地區內醫師數量的多或少，對有保險者的門診醫療利用機率及次數並未造成顯著差異。結論：臺灣地區醫 療資源分佈雖不完全平均，但並未導致民眾醫療利用顯著的差異。是否表示就醫可近性較差地區民眾已付出較高的時間及交通成本以尋求必要的醫療，值得注意與改善。

　　　　　Objective: To examine the effect of the number of physicians on the utilization of ambulatory services for insured persons. Methods: The insured population was the target population in this study, and a two-part analysis was used in this study. To test the impact of physician supply on ambulatory care utilization, we categorized the medical care sub-regions for three levels according to the density of medical doctors: low, median, and high. Information about individuals' medical utilization was collected from the 1994 Taiwan Health Interview Survey (THIS). The physician-to-population ratios for each region were obtained from the 1994 Medical Care Manpower Survey in Taiwan compiled by the Department of Health and from the Taiwan-Fukien Demographic Fact Book published by the Ministry of the Interior, Republic of China. Results: After controlling for extraneous factors, the effect of the number of community physicians on the use of ambulatory services by the insured was not found to be statistically signific ant for the differences among the high, median, and low groups. Conclusion: Therefore, there is insufficient evidence to support the view that the presence of fewer community physicians have discouraged the utilization of ambulatory services by the insured. However, whether this indicates that people with less medical resources where they live have paid higher time and transportation costs to obtain the needed care deserves further investigation for policy formulation.