[Socioeconomic variables in public health research in Mexico].

The results presented here show that there is no single variable nor a particular set of variables which are ideal to stratify the Mexican population in socioeconomic terms. This means that it is necessary to select indicators appropriate to each case, taking into consideration their specificity of meaning, their meaning with regard to the study problem and, naturally, also the objective and conceptual framework of the research, in the present case, public health research. The selection of indicators needs to be based on practical/methodological and theoretical considerations. Some of these are discussed in the present paper. Regaining the conceptual meaning of the indicators is fundamental and this is why a discussion of the concepts of social class, social strata, social inequality and poverty was undertaken. The practical/methodological criteria which were examined, include such elements as the type of variable used (dichotomic, categorical, continuous, etc.). To this end, socioeconomic variables of the National Fertility and Health Survey were analyzed, as well as the variable "poverty", which was constructed with data from the National Household Income and Expenditures Survey. As a result, outlines were drawn for a better understanding, utilization and measurement of socioeconomic indicators in public health research in Mexico.