In the United States, "Health Maintenance Organisations" (HMO) undertook to master the growth of the costs of the health. Numerous patients complained about the quality of the care under this regime and about limitations that HMO imposed on them, in particular in access to care. To the quality care issues under this regime added the anxieties conceming patients’ satisfaction. Has the former degraded under the regime HMO? On this subject, numerous studies compare the satisfaction of the patients under the regime HMO to that of the patients in the traditional System with "Fee-For-Service payment" (FFS). They also concern the vulnerable patients, such as the old or deprived persons, illustrating how difficult it is to measure of quality.