Sex differences in the association between marital status and the risk of cardiovascular,cancer,and all-cause mortality:a systematic review and metaanalysis of 7,881,040 individuals

Purpose:To ascertain whether sex differences exist in the relationship between marital status and cardiovascular diseases(CVD),coronary heart disease(CHD),cancer and 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 to obtain sex-specific relative risks and their 95%confidence intervals.These were used to derive the women-to-men ratio of RRs(RRR)and 95%CI for each study.RRs and RRRs for each outcome were then pooled using random effects inverse-variance weighted meta-analysis.Results:Twenty-one studies with 7,891,623 individuals and 1,888,752 deaths were included in the meta-analysis.Compared with married individuals,being unmarried was significantly associated with all-cause,cancer,CVD and coronary heart disease mortalities for both sexes.However,the association with CVD and all-cause mortality was stronger in men.Being divorced/separated was associated with a higher risk of all-cause mortality in men and a stronger risk of cancer and CVD mortality.The pooled ratio for women versus men showed 31 and 9%greater risk of stroke mortality and all-cause mortality associated with never married in men than in women.Conclusions:Being unmarried conferred higher risk of stroke and all-cause mortality for men than women.Moreover,divorced/separated men had 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 by these associations.