Effect of same-sex marriage legalisation on the health of ethnic minority lesbian, gay and bisexual people: a quasi-experimental study

Background The UK legalised same-sex marriage in 2014. We examine whether same-sex marriage legalisation (SSML), an exogenous policy change, affected the health outcomes among ethnic minority lesbian, gay, bisexual and other (LGB+) individuals. Methods Using the UK Household Longitudinal Survey, we applied the Callaway and Sant’Anna difference-in-differences to compare physical and mental health across (a) ethnic LGB+ individuals (treatment group), (b) ethnic heterosexual individuals (control group 1) and (c) British white LGB+ individual (control group 2). The study cohort (n=7054) comprised individuals aged 16+ years at baseline in 2011, and were employed in the study period (2011–2019). The outcomes included physical component scores from the short-form 12 health survey (physical component score (PCS-12)), long-standing illnesses and psychological distress (General Health Questionnaire (GHQ)). Results After SSML, the PCS-12 among the ethnic LGB+ individuals improved significantly compared with both ethnic heterosexuals and British white LGB+ individuals (2.081, 95% CI 0.487 to 3.675). While no clear patterns were found for long-standing illnesses, the GHQ in the treatment group had modest decreases relative to ethnic heterosexuals, and relative to British white LGB+ individuals, by year 2 after SSML. Conclusion SSML in the UK led to improved physical functioning and reduced psychological distress in ethnic minority LGB+ individuals. Our study shows that ethnic LGB+ individuals may derive even greater health benefits than British white LGB+ people, providing evidence that SSML may help address racial health inequalities within LGB+ communities. As countries worldwide consider legalising same-sex marriage, it is imperative for policymakers to consider the health consequences for sexual and ethnic minorities.