For the first time, the census will ask your sexual orientation. My new study shows why it matters

For the first time, the Australian census will ask about participants' sexual orientation. This new question, set to appear on August 11, will allow researchers to examine health disparities across the entire population for the first time. The information gathered will influence public spending, healthcare provision, and government policy.

My recent research, peer-reviewed and accepted for publication in the American Journal of Public Health, reveals that Australians in same-sex relationships have higher premature mortality rates, including by suicide. However, this change in the census means that, for the first time, researchers can analyze the impact of sexual orientation on health across the whole population.

The census question asks participants to describe their sexual orientation, with options including straight, gay or lesbian, bisexual, pansexual, asexual, or a custom term. This optional question is available to those aged 16 and over. The wording was determined through extensive public consultation and testing, reflecting years of advocacy by community organizations and researchers.

In Australia, approximately 3.6% of the population identifies as lesbian, gay, bisexual, pansexual, asexual, or another diverse sexuality. Historically, limited and incomplete data have been used to study this population's health, often resulting in insufficient sample sizes for rare but critical outcomes. My study, using 2011 census data linked to death records, shows that Australians in same-sex relationships face a significantly higher risk of premature death compared to those in different-sex relationships.

For every 1,000 women in different-sex relationships, 983 were alive after 12 years, but only 979 for those in same-sex relationships. Similarly, for men, 971 out of 1,000 in different-sex relationships remained alive after 12 years, compared to 963 for those in same-sex relationships. This translates to about one in five premature deaths among people in same-sex relationships being "excess" or beyond what would be expected in different-sex relationships.

The primary cause of premature deaths among women in same-sex relationships is suicide, accounting for nearly 12% of such deaths, while for men, it is about 13%. These inequalities persist six years after the legalization of marriage equality, showing no signs of improvement. While the study focused on a subset of Australians in same-sex relationships, the lack of data on sexual orientation has likely undercounted the true scale of health disparities.

The new census question will provide vital insights into the health of people with diverse sexual orientations, enabling governments to allocate resources more effectively and target interventions where they are most needed.