Health inequalities among non-lesbian, gay and bisexual sexual minority adolescents: Findings from a national UK cross-sectional study

Sexual minority individuals who identify with sexual identities other than lesbian, gay, bisexual (LGB) have increased risk for poor mental health. However, most health research focuses on LGB groups often excluding other sexual minority identities. This study examined 1) sociodemographic characteristics and 2) a range of health indicators and health-related behaviours in other sexual minority identities ([OSI], including those who do not disclose their sexual identity) and in comparison, to LGB and heterosexual peers using data from the UK-wide Millennium Cohort Study. This study included 9,998 adolescents (53% assigned male sex at birth, 19.8% LGB and 2% OSI) aged 17 years. Sexual identity was self-reported, and included heterosexual [reference], sexual minority [LGB] and OSI (other sexual minority identities, did not disclose, not known). Multinomial logistic regression examined sociodemographic characteristics (assigned sex at birth [ASAB], gender, ethnicity and socioeconomic position) of the OSI group in comparison to the heterosexual group. Associations between sexual identity and mental (like psychological distress, self-harm, attempted suicide) and general (like obesity) health, and health-related behaviours (like smoking, alcohol frequency) were analysed using multivariable logistic regression. Female ASAB participants (Relative risk ratio [RRR] 2.62, 95% CI 1.81-3.77) and those from families with lower parental income were more likely to be classified in the OSI group, compared to heterosexuals. OSI individuals had increased odds for all mental health (example, Prevalence Odds Ratio [POR] 3.7, 2.55-5.35 for psychological distress, POR 2.73, 1.71-4.35 for attempted suicide), and general health indicators (example, POR 1.77, 1.22-2.57 for obesity), most often similar in strength to LGB peers. OSI individuals had lower PORs for most health-related behaviours (example, POR 0.46, 0.32-0.67 for ever smoking, POR 0.60, 0.39-0.93 for ever drug use, POR 0.25, 0.17-0.39 for ever had sex). Compared to heterosexual adolescents, those who identify with OSI have substantially increased prevalence for a wide range of health problems comparable in strength to the LGB group. However, the OSI group did not have increased odds for health-related behaviours as observed in the LGB group. Future studies should include OSI individuals in research on sexual minority health ensuring better representation of all sexual identities.