The interrelationship between income, health and employment status.

BACKGROUND: The aim of the study was to test the hypothesis that the relatively strong association between income and health compared to that between education/occupation and health, can partly be interpreted in terms of an association between employment status and health.
METHODS: Health indicators used were the prevalence of one or more chronic conditions, and perceived general health. Data were generated from a postal survey, part of the baseline data collection of a Dutch prospective cohort study on socioeconomic inequalities in health.
RESULTS: After controlling for differences in other socioeconomic indicators, the association between income and health was found to be stronger than that between occupation or education and health. Most of the difference in strength was found to be due to employment status, especially among men. Controlling for employment status, and controlling for the distribution of those with a long-term work disability in particular, reduced the risks of lower income groups, whereas the risks of lower educational and occupational groups hardly changed.
CONCLUSIONS: These results suggest that the relatively strong association between income and health can for a large part be interpreted in terms of an interrelationship between employment status, income and health. More specifically, it is largely due to the concentration of the long-term disabled in lower income groups. This indicates the importance of the selection mechanism, as these groups are excluded from paid employment because of their health status, leading to a lowering of income. However, income was still found to be related to perceived general health after controlling for employment status especially among women. This suggests that an explanation in terms of an effect of material factors on health may also be important.