Krakauer H, Jacoby I, Millman M, Lukomnik J E
Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, School of Medicine, Bethesda, MD 20814-4799, USA.
Health Serv Res. 1996 Jun;31(2):191-211.
We assess the effect of variations in the supply and specialty distribution of physicians on admission rates for ambulatory care-sensitive conditions (ACS) and for all causes, and on mortality rates among Medicare beneficiaries of various health care service areas (HCSA).
For the Medicare beneficiaries, sources were the Health Care Financing Administration's 1992 enrollment and impatient (Part A) files for a 5 percent sample of that population; for the overall populations and for the medical resources of the HCSAs, the Area Resource File.
This observational, cross-sectional study employed multiple linear regression to assess the influence of population characteristics and of the supply of physicians on hospital admissions, and Poisson regression in the analysis of the factors that affect mortality.
Physician supply levels vary nearly fourfold or more when comparing the top and bottom deciles of the HCSAs, Medicare admissions for ACS conditions vary about threefold, and admission rates for all causes and mortality rates vary about 1.5-fold. Physician supply levels and distributions have very little influence on ACS admission rates, and even less on the admissions for all causes and on mortality, except in HCSAs with very low physician supply levels (one-fourth the national average or less). However, these HCSAs account for only about 1 percent of the U.S. population.
Physician supply levels and the proportions of specialists and generalists have negligible effects on health status as measured by mortality rates and by rates of admission for all causes and for conditions presumed to be sensitive to the adequacy of ambulatory care. Reductions in admissions for such conditions are not likely to be achieved through broadening of insurance to levels that exist under Medicare, nor through increases in the supply of physicians, nor, conversely, through a reduction in any presumed oversupply of physicians.
我们评估医生供应及专业分布的变化对门诊医疗敏感型疾病（ACS）和所有病因的住院率，以及不同医疗服务区域（HCSA）医疗保险受益人的死亡率的影响。
对于医疗保险受益人，数据来源是医疗保健财务管理局1992年针对该人群5%样本的参保和非住院（A部分）档案；对于总体人群和HCSA的医疗资源，数据来源是区域资源档案。
这项观察性横断面研究采用多元线性回归来评估人口特征和医生供应对住院率的影响，并采用泊松回归分析影响死亡率的因素。
比较HCSA的最高和最低十分位数时，医生供应水平相差近四倍或更多，ACS疾病的医疗保险住院率相差约三倍，所有病因的住院率和死亡率相差约1.5倍。医生供应水平和分布对ACS住院率影响很小，对所有病因的住院率和死亡率影响更小，除非在医生供应水平非常低（为全国平均水平的四分之一或更低）的HCSA中。然而，这些HCSA仅占美国人口的约1%。
以死亡率、所有病因的住院率以及假定对门诊医疗充足性敏感的疾病的住院率来衡量，医生供应水平以及专科医生和全科医生的比例对健康状况的影响可忽略不计。通过将保险范围扩大到医疗保险现有水平、增加医生供应，或者相反，通过减少任何假定的医生供应过剩，都不太可能降低此类疾病的住院率。
