All-Cause and External-Cause Mortality Disparities Among Australians in Same-Sex Relationships Before and After Marriage Equality: A Nationwide Cohort Study, 2011-2023.

Abstract

Objectives. To examine secular trends in mortality among Australians in same-sex and different-sex relationships. Methods. Using Australian Census-linked mortality records (2011-2023), I used Cox proportional hazard models to estimate all-cause and external-cause mortality risk among adults in same-sex relationships (n = 54 529) and different-sex relationships (n = 7 923 328), separately by sex. Inverse probability weights balanced comparators on age, educational attainment, and household income. I stratified results into periods before and after Australia's 2017 legalization of same-sex marriage. Results. Compared with those in different-sex relationships, women and men in same-sex relation..