Morten Frisch (Statens Serum Institut, Copenhagen, and Aalborg University, Aalborg) and statistician Jacob Simonsen (Statens Serum Institut, Copenhagen) reported that the mortality rate for men in same-sex marriages has dropped markedly since the 1990s while the mortality rate for same-sex married women rose to the highest levels in recent history in March 12, 2013, issue of the International Journal of Epidemiology.
The researchers accessed Denmark's Civil Registration System to come to the conclusions. The study included data from 6.5 million people making this the largest study ever conducted concerning sexual orientation, marriage, and longevity.
Breast cancer and suicide were the largest contributors to lesbian mortality.
“Compared with people married to a member of the opposite sex, hazard ratios for overall mortality were consistently elevated in unmarried, divorced, widowed, or same-sex married people. Likewise, compared with people cohabiting with a member of the opposite sex cohabiting, hazard ratios for overall mortality were consistently elevated among people who lived alone, with parents, in multi-adult households, or in same-sex cohabitation.”
A similar study conducted in the United States by Dr. Hui Liu, an assistant professor of sociology at Michigan State University, found that the odds of reporting poor or fair health were about 61 percent higher for same-sex cohabiting men than for men in heterosexual marriage, and the odds of reporting poor to fair health were about 46 percent higher for same-sex cohabiting women than for women in heterosexual marriages.
The study was based on pooled data from 1997 to 2009 National Health Interview Surveys and compared the self reported health status of 1,659 gay couples living together and a similar number of married heterosexuals.