The results of the RAND Health Insurance Experiment are important in the debates on access to and financing of health services, and direct charges to patients. The study randomly assigned people in six areas in the United States to different health insurance plans for periods of three or five years. Elderly people were excluded (as most already had access to free care through Medicare). Around 2000 families were included in the experiment.

The aim of the study was to test in experimental conditions the response of people to different charges for using health services. Some people were enrolled in plans that provided care free at the point of use. Others had to pay varying proportions of the cost. For those paying some …