Gender differences in the association between mortality ansocioeconomic-marital status in the moli-sani study cohort

Introduction. Socioeconomic disparities in health outcomes are well-established, with lower-status groups being at higher risk of disease/mortality. However, few are the studies which estimated possible gender-related differences in the association between the socioeconomic status (SES) and mortality. We aimed to investigate gender differences in the association between socioeconomic indicators and mortality, as well as the possible mechanisms of such association. Methods. Longitudinal analysis of 10,655 men (mean age 55.7 ± 11.8) and 11,539 women (mean age 54.6 ± 11.5) enrolled in the Moli-sani Study, Italy (2005-2010). Education level, housing tenure and occupational social class were used as indicators of SES, while marital status represented the social factor. We tested health conditions (e.g. history of disease) and the behavioural (e.g. diet), traditional (e.g. blood cholesterol) and inflammatory (e.g. C-reactive protein) pathways as mediators of the SES-mortality gradient. Potential gender-related differences were tested by appropriate interaction terms. Results. In the course of an average follow-up of 8.3 years (182,924 person-years), 1155 all-cause deaths were established. Among men, lower education and poor housing-tenure were associated with a 56% and a 72% increase in the risk of death, respectively; unemployed/unclassified men reported a lower survival rate versus professionals; likewise, divorced men showed to be at higher risk compared to their married counterparts. None of the SES factors was associated with reduced survival among women. Behavioural factors explained up to 23% of SES disparities in mortality among men. The mortality risk associated with housing tenure was higher in men than in women (p for interaction = 0.048). In addition, marital status and poor housing interacted among men, but less so among women, with a 2-fold increase in the risk of death among unmarried men with lower housing-tenure. On the contrary, the association between education and mortality did not vary with gender. Discussion. Findings from this large cohort enrolled among the Italian general population indicate a clear SES gradient in mortality. Gender appears to modify the association between material SES indicators and the risk of death, but not that between education and mortality. Marital status and poor material resources interacted in such a way that unmarried men were at higher risk of long-term mortality than their married counterparts.