[Evaluation of the socioeconomic status in epidemiological surveys: hypotheses of research in the Brianza area MONICA project].

Socio-economic status (SES) has been reported as a causative factor of increasing health inequalities in industrialized countries. The phenomenon has been particularly investigated for job related diseases, including cardiovascular disease and risk. The group of occupational medicine specialists in the world wide MONItoring program of CARdiovascular disease (WHO-MONICA Project) is now producing a number of hypotheses about the application of internationally defined criteria and tools for SES evaluation in the Italian area of the Project, Area Brianza. After a short review of some main conceptual and methodological problems, a proposal is presented of an SES index, derived from the pooled data of two population surveys carried out in this area. From a randomized sample of 3200 residents, 25-64 years old, stratified by sex and age decade, 1731 subjects, 594 females and 1137 males, employed at the time of the screening were extracted. Four variables were considered: age, education, occupational level and job-strain (according to the Karasek-Theorell model) by which each subject was classified in three levels--high, medium, low--of education and occupation, whose combination was used to obtain as many levels of socio-economic status. This a method of building an SES index is based on a sequence of approximations following two essential criteria: limitation of the variables to be surveyed, through standardized procedures; ability to identify the "low" SES category, presumably more at risk for disease.