Income, occupational position, qualification and health inequalities-competing risks? (Comparing indicators of social status)

Study objective-The debate on health inequalities has shifted from the consequences of occupational position, as expressed in the Registrar General's classification, to consequences of material living conditions. This change in interest occurred without comparative analyses of different sources of health inequalities. Thus this study investigated the relative contribution of "material resources" (income), "qualification" and "occupational position" for explaining social differentials in mortality. Design and setting-Analyses were performed with records from a statutory health insurance in West Germany. The analyses were performed with data of 84 814 employed men and women between 25 and 65 years of age who were insured between 1987 and 1995 for at least 150 days. Results-The three indicators were statistically associated, but not strong enough to warrant the conclusion that they share the same empirical content. The relative risk (hazard rate) for income by controlling for occupational position and gender for the highest as compared with the lowest category was 1.99 (95% CI 1.66, 2.39). The corresponding relative risk for income by controlling for qualification and gender was 2.03 (95% CI 1.68, 2.46). In both multivariate analyses, the effects of occupational position and qualification were no longer interpretable because of large confidence intervals. In sum, income related relative mortality risks were the comparably highest, white qualification and occupational position were no longer substantial. Conclusions-The results emphasise the present discussion on the consequences of material living conditions. Income on the one hand and qualification and occupational position on the other are largely independent. Mortality related effects of income override those of the other socioeconomic status indicators. However, seen in a time perspective, qualification may still have a placement function at least for the first occupational position.