Understanding sexual orientation and health in Canada: Who are we capturing and who are we missing using the Statistics Canada sexual orientation question?

OBJECTIVE: Public health research on inequalities in Canada depends heavily on population data sets such as the Canadian Community Health Survey. While sexual orientation has three dimensions – identity, behaviour and attraction – Statistics Canada and public health agencies assess sexual orientation with a single questionnaire item on identity, defined behaviourally. This study aims to evaluate this item, to allow for clearer interpretation of sexual orientation frequencies and inequalities. METHODS: Through an online convenience sampling of Canadians ≥14 years of age, participants (n = 311) completed the Statistics Canada question and a second set of sexual orientation questions. RESULTS: The single-item question had an 85.8% sensitivity in capturing sexual minorities, broadly defined by their sexual identity, lifetime behaviour and attraction. Kappa statistic for agreement between the single item and sexual identity was 0.89; with past year, lifetime behaviour and attraction were 0.39, 0.48 and 0.57 respectively. The item captured 99.3% of those with a sexual minority identity, 84.2% of those with any lifetime same-sex partners, 98.4% with a past-year same-sex partner, and 97.8% who indicated at least equal attraction to same-sex persons. CONCLUSION: Findings from Statistics Canada surveys can be best interpreted as applying to those who identify as sexual minorities. Analyses using this measure will underidentify those with same-sex partners or attractions who do not identify as a sexual minority, and should be interpreted accordingly. To understand patterns of sexual minority health in Canada, there is a need to incorporate other dimensions of sexual orientation.