OBJECTIVES : The medical microstructures designed in 2000 were developed to respond to the difficulties encountered in the care of people with addictive behaviours. These microstructures of proximity are established within the cabinet of general practitioners in association with a psychologist and a social worker. The aim of the study is to evaluate the cost-utility ratio of microstructure networks (MSN) in patients undergoing opioid substitution therapy management.

METHODS : A qualitative first stage identified the criteria involved in the opioid management dependence, according to both physicians and patients for MSN or conventional follow-up. A second quantitative stage described practices, characteristics and quantified the preferences of physicians and patients against the criteria. This quantification was done from a method derived from the theory of utility multi-attribute.

RESULTS : During the first stage, 16 interviews were conducted: 8 doctors and 8 patients. They described the differentiation between the MSN and the conventional care, which guided the definition of 8 utility criteria.

For physicians, the most important criterion is “the possibility for users to change lives”, contributing to more than a quarter of the total utility. Next are “the responsiveness of the doctor”, “access to the doctor” and “control of consumption” contributing around 14 % each to the total utility. Finally, criteria such as “HCV testing”, the “ability to negotiate treatment”, “continuity of care”, and “access to other professionals” amount to less than 10%. On the patient side, preferences differ little from those of doctors, although “access to an experienced doctor” is the most valued criterion and “control of consumption” is given as much importance as changing lives.

CONCLUSIONS : Our study shows an indicator in favour of microstructures: users in MSN offices are more satisfied. From physicians’ standpoint, MSN doctors are more comfortable in tracking drug users, perhaps because they are less isolated in their care.