Preventable mortality among sexual minority Canadians

Abstract

Background: Epidemiologic studies point to multiple health inequities among sexual minority people, but few studies have examined mortality. Some causes of death are more preventable than others, and access to prevention is theorized to follow patterns of access to social and material resources. The objective of this study is to compare estimates of preventable mortality between sexual minority (SM)-i.e., bisexual, lesbian, gay-and heterosexual adults in Canada.

Methods: A population-based retrospective cohort with 442,260 (unweighted N) Canadian adults, ages 18-59 years, was drawn from the Canadian Community Health Survey/Canadian Mortality Database linked database (2003-2017). The Rutstein preventability rating index was used to classify cause-specific mortality (low/high). Longitudinal analyses were conducted using Cox proportional hazards models.

Results: SM respondents had higher hazard of all-cause mortality (unadjusted hazard ratio [uHR] 1.28, 95% CI 1.06, 1.55). The uHR increased when the outcome was limited to highly-preventable causes of mortality (uHR 1.43, 95% CI 1.14, 1.80). The uHR further increased in sensitivity analyses using higher thresholds of the Rutstein index. SM respondents had higher hazard of cause-specific mortality for heart disease (uHR 1.53, 95% CI 1.03, 2.29), accidents (uHR 1.97, 95% CI 1.01, 3.86), HIV (uHR 75.69, 95% CI 18.77, 305.20), and suicide (uHR 2.22, 95% CI 0.93, 5.30) but not for cancer (uHR 0.86, 95% CI 0.60, 1.25). The adjusted HR (aHR) for highly-preventable mortality was not attenuated by adjustment for confounders (aHR 1.57, 95% CI 1.20, 2.05) but was reduced by adjustment for hypothesized mediators relating to access to social and material resources (marital status, children, income, education; aHR 1.11, 95% CI 0.78, 1.58).

Conclusions: Preventable mortality was elevated for SM Canadians compared to heterosexuals. Early and broad access to sexual minority-affirming primary and preventive healthcare should be expanded.

Keywords: Mortality; Sexual and gender minorities; Social determinants of health.

Fig. 1

Conceptual and analytical model of hypothesized causal pathways between sexual minority status and preventable mortality, based on fundamental cause theory (Link and Phelan, 1995); ^e explanatory variable; ^o outcome; ^m mediator; ^c confounder.

Fig. 2

Cumulative survival by sexual orientation and preventability of death (≥4.0 vs. <4.0), Canadian Community Health Survey-Canadian Mortality Database cohort, Canada, 2003–2017 (Kaplan-Meier curve); Note. SM = sexual minority; Het = heterosexual.