Cause-specific mortality by partnership status: simultaneous analysis using longitudinal data from England and Wales

Background This paper examines cause-specific mortality by partnership status. Although non-marital cohabitation has spread rapidly in industrialised countries, only a few studies have investigated mortality by partnership status and no recent study has investigated cause-specific mortality by partnership status. Methods We use data from the Office for National Statistics Longitudinal Study and apply competing risks survival models. Results The simultaneous analysis shows that married individuals have lower mortality than non-married from circulatory, respiratory, digestive, alcohol and accident related causes of deaths, but not from cancer. The analysis by partnership status reveals that once we distinguish premarital and postmarital cohabitants from other non-married groups, the differences between partnered and non-partnered individuals become even more pronounced for all causes of death; this is largely due to similar cause-specific mortality levels between married and cohabiting individuals. Conclusions With declining marriage rates and the spread of cohabitation and separation, a distinction between partnered and non-partnered individuals is critical to understanding whether and how having a partner shapes the individuals' health behaviour and mortality. The cause-specific analysis supports both the importance of selection into partnership and the protective effect of living with someone together.