The impact of cost sharing on emergency department use

The authors of this report 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 percent, subject to an income-related upper limit on out-of-pocket expenses. It was concluded 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