Indicators of social class. A comparative appraisal of measures for use in epidemiological studies

Various indicators of social class were compared in a community health survey in Jerusalem in order to appraise their value in detecting associations with health characteristics. Correlations among the indicators and between them and selected health-relevant variables were measured. The results suggested that there was little to choose between the occupational scales tested (an adaptation of the British Registrar-General's scale, a prestige scale, and a socio-economic status scale) for use as general indicators of social class in epidemiological studies, as the correlations between them were very high and the patterns of their correlations with the health variables were very similar. Correlations with some health variables became weaker when less detailed occupational data were used. Other indicators of social class (education, family income, household crowding, an authority rating and an amenities score) were not strongly correlated with occupation, and there were differences in their associations with the health variables, indicating that conclusions about the relationship between health and social class are not insensitive to the measure used. Despite the discrepancies, the patterns of associations with the health measures were broadly similar for occupational scales, education and income, suggesting that if a single measure is to be used there may for some purposes be little to choose between these major indicators. The fairly low correlations among these different indicators of social class suggest that there may be considerable gains from using more than one measure, so as to increase the chance that an association with social class will be detected, to permit appraisal of independent effects and important interactions between indicators, and to increase the overall explanatory or predictive power of the model. The choice of indicators should be determined by practical considerations and by the conceptual framework with respect to the social-class relationships of the health characteristics under study.