O'Grady K F, Manning W G, Newhouse J P, Brook R H
N Engl J Med. 1985 Aug 22;313(8):484-90. doi: 10.1056/NEJM198508223130806.
We studied the effect of insurance coverage on the use of emergency department services, using data from a national trial of cost sharing in health insurance. A total of 3973 persons below the age of 62 years were randomly assigned to fee-for-service health insurance plans with coinsurance rates of 0, 25, 50, or 95 per cent, subject to an income-related upper limit on out-of-pocket expenses. Persons with no cost sharing had emergency department expenses that were 42 per cent higher than those for persons on the 95 per cent plan (P less than 0.01) and about 16 per cent higher than those for persons with smaller amounts of cost sharing. Without cost sharing, emergency department visits for less serious diagnoses (e.g., abrasions) increased three times as much as did visits for more serious diagnoses (e.g., lacerations). After control for insurance, persons in the lower third of the income distribution had emergency department expenses that were 64 per cent higher than those in the upper third (P less than 0.001) and received a greater proportion of their ambulatory care in the emergency department. We conclude that the absence of cost sharing results in significantly greater emergency department use than does insurance with cost sharing. A disproportionate amount of the increased use involves less serious conditions.
我们利用一项全国性医疗保险费用分担试验的数据，研究了保险覆盖范围对急诊服务使用情况的影响。共有3973名62岁以下的人被随机分配到按服务收费的医疗保险计划中，其共付率分别为0%、25%、50%或95%，且自付费用有与收入相关的上限。无费用分担的人的急诊费用比95%共付率计划的人高出42%（P<0.01），比费用分担较少的人高出约16%。在无费用分担的情况下，因不太严重诊断（如擦伤）而进行的急诊就诊次数的增加幅度是因更严重诊断（如撕裂伤）而进行的急诊就诊次数增加幅度的三倍。在控制了保险因素后，收入分布处于下三分之一的人的急诊费用比上三分之一的人高出64%（P<0.001），且他们在急诊部门接受的门诊护理比例更高。我们得出结论，与有费用分担的保险相比，无费用分担会导致急诊服务的使用显著增加。增加的使用量中不成比例的部分涉及不太严重的病症。
