[Utilization of health services]

Health services utilization has been associated to several socio-demographic factors, as age, gender, or socio-economic status. It has also been associated to the organizational structure and finance of health care, and to health status of the individuals. In the present article main results of studies of health services utilization, are reviewed, with special emphasis on primary health care. The main factor associated with health services utilization is health services need as measured by individual's health status. The rest of variables have a minor role when jointly analyzed. When utilization of services is caused for a preventive visit, variables related with health status are less explicit. Methodological limitations of these studies and problems when analyzing equity in utilization of health services are also discussed.