Socioeconomic inequalities in mortality. Explanatory and contextual perspective: Evidence from the Nord-Trøndelag Health Study

Abstract

Aims: This thesis aimed to expand prior knowledge about the relative importance of different groups of explanatory factors (material, psychosocial, behavioral and biomedical) to explaining socioeconomic inequalities in mortality in men and women. In addition, we aimed to examine the importance of partner's socioeconomic position and household, together with other social contexts for one's mortality.

Materials: The Nord-Trondelag Health Study, HUNT 1 (1984-86) and HUNT 2 (1995-97).

Results: We found socioeconomic gradients in mortality in men and women. In men, material and psychosocial factors were the most important factors in explaining income inequalities in mortality, whilst psychosocial and behavioural factors were the most important in explaining educational inequalities in mortality. In women, behavioural factors were most important in explaining both educational and income inequalities in mortality. Accounting for change in behavior provided the largest improvement in explained inequalities in mortality for both sexes. Repeated measurement of psychosocial factors explained the largest share of income inequalities in mortality for men, but the contribution of repeated measurement of these factors to improvement in explanation was negligible. The contribution of biomedical factors to the explanation of health inequalities was very modest in both sexes. When investigating households, wife's education and husband's occupation and income were the most important predictors of mortality across partner relationships. When comparing different contextual levels, most clustering of mortality was observed within households. Observed variance in mortality in wards and municipalities was quite small.

Conclusions: Behavioral factors and their change explained a large share of excess mortality in low income women and in low educated men and women, whereas baseline psychosocial factors were in particular important in explaining excess mortality in low income men. In addition, we provided evidence that household matters for one`s health and that men`s and women`s mortality is related to partner`s socioeconomic position, though by presumably different mechanisms. Our findings underscore the importance of public health policies to focus not only on behavioral risks in socioeconomically disadvantaged men and women, but also on psychosocial factors relatively early in men`s life course. In addition, measures targeted on socioeconomically disadvantaged households might contribute to diminish social inequalities in health