A brief analysis of the trends in the incorporation of social aspects into epidemiological studies, is presented. In recent analysis some concepts have been considered very important. Among them, the concept of "social class" has been detached and is used in epidemiological research. Some questions about difficulties in the concept of social class and its application are presented, as well as a scheme for the application of the concept of social class based on data on ownership of the means of production, occupational position and occupational categories. For the owners, data about income and number of employees were used to distinguish between entrepreuner bourgeoisie and little bourgeoisie. Finally some data collected during the use of this scheme proposing discrimination of sub-divisions' of social classes in a study on morbidity and used of medicine carried out in Ribeirão Preto, SP, are presented.
Epidemiology; Social class; Health and disease
