Abstract
Background
Marital status has been identified as an important social factor associated with mortality. In current epidemiologic research, being unmarried was observed to be a suboptimal health status in the global population. The growing number of unmarried people has health implications, in light of evidence suggesting that it is associated with an increase in the incidence of various diseases and high mortality. Few attempts have been made to produce an overall estimate and sufficiently clarified of the sex difference between unmarried status and mortality risks, this is still a matter of debate.
Purpose
To ascertain whether sex differences exist in the relationship between marital status and cardiovascular disease (CVD), cancer, all-cause mortality in the general population and to explore the potential effect of age, location, the duration of follow-up and publication years on these outcomes.
Methods
A systematic search was performed in PubMed and EMBASE from inception through to April 2018 and review of references. We used the sex-specific RRs (relative risk) to derive the women-to-men ratio of RRs (RRR) and 95% CIs from each study. Subsequently, the RRR for each outcome was pooled with random effects meta-analysis weighted by the inverse of the variances of the log RRRs.
Results
Twenty-one studies with 7,881,040 individuals were included for meta-analysis. Compared with married individuals, being unmarried was significantly associated with all-cause mortality, cancer mortality, CVD mortality and coronary heart disease (CHD) mortality, especially for singles, for both sexes (Figure 1). However, the association with death from all-cause and CVD was significantly stronger in men. Compared with women who were divorced/separated, divorced/separated men had significantly higher risk of all-cause mortality, cancer mortality and CVD mortality. Moreover, never married men had 31% and 9% higher excess risk of stroke mortality and all-cause mortality, respectively, compared with never married women. No sex differences were observed concerning the impact of any unmarried status on CHD mortality.
Conclusions
Being unmarried (widowed, divorced/separated or never married) conferred higher excess risk of stroke mortality and all-cause mortality for men than women. Moreover, divorced/separated men had significantly higher risk of cancer mortality and CVD mortality. Further studies are warranted to clarify the biological, behavioral, and/or social mechanisms involved in sex differences driving these associations.
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