Marital status and ischaemic heart disease incidence and mortality in women: a prospective study

Background Being married has been associated with a lower risk of mortality from ischaemic heart disease (IHD) in men, but there is less evidence of an association for women, and it is unclear whether the associations with being married are similar for incident and for fatal IHD. Our aim was to examine the relation between marital status and IHD incidence and mortality in a large cohort of UK women. Methods A total of 734,626 women (mean age 59.7 (SD 5) years at baseline) without previous heart disease, stroke, or cancer, were followed prospectively for cause-specific hospital admissions and deaths. We used Cox regression models to calculate adjusted relative risks (RRs) for IHD in partnered (married or living with a partner) versus unpartnered (including divorced, separated, widowed, or never married) women, and investigated the role of 14 socio-economic, lifestyle and other potential confounding factors. Results Overall 81% of women reported being partnered. Compared to those who were not partnered, partnered women were less likely to live in deprived areas, to smoke, or to be physically inactive, but had a higher alcohol intake; there was no difference in body mass index. During 8.8 years of follow-up, 30,747 women had a first IHD event (hospital admission or death) and 2,148 died from IHD. Partnered women had a similar risk of a first IHD event to unpartnered women (adjusted RR=0.99, 95% confidence interval (CI) 0.961.02), but a significantly lower risk of IHD mortality (adjusted RR=0.72, 95% CI 0.66-0.80, p<0.0001). The reduced risk of IHD death for partnered women was evident both in women with and without a prior IHD hospital admission (respectively: adjusted RR=0.72, 95% CI 0.60-0.85, p<0.0001, n=683; and 0.70, 95% CI 0.62-0.78, p<0.0001, n=1,465). These findings did not vary appreciably in women of different socio-economic groups and with different lifestyle and other factors. Conclusions After adjustment for socioeconomic, lifestyle and other factors, being partnered was not associated with women’s risk of developing IHD in this cohort, but partnered women had a substantially lower IHD mortality than unpartnered women.