Importance: Coming out as lesbian, gay, bisexual, or other identities besides heterosexual (LGB+) may represent a susceptible period for cigarette smoking initiation in youth and young adults.
Objective: To assess whether young people who change their sexual identity have higher risk of cigarette smoking initiation and current smoking compared with those with consistent sexual identities.
Design, setting, and participants: This cohort study used data from the nationally representative Population Assessment of Tobacco and Health study (wave 1, 2013-2014; wave 2, 2014-2015; wave 3, 2015-2016; wave 4, 2016-2018). Youth and young adults aged 14 to 29 years who were never smokers at wave 1 were included in this study. Analysis began October 2018 and ended June 2020.
Exposures: Consistent sexual identity (consistently heterosexual, consistently LGB+) vs changing sexual identity (coming out as LGB+, other LGB+ patterns) based on 4 waves of sexual identity data. Identities were further classified by distinguishing between bisexual and lesbian, gay, and other nonheterosexual identities.
Main outcomes and measures: Smoking initiation and current cigarette smoking at wave 4.
Results: Among 7843 individuals who never smoked at wave 1, 6991 (90.7%) reported a consistent sexual identity, and 852 (9.3%) changed sexual identity across waves. The mean (SE) baseline age of participants who reported consistent heterosexuality was 20.1 (0.8) years; consistently LGB+, 20.0 (3.7) years; coming out as LGB+, 18.0 (2.9) years, and other LGB+ pattern, 20.3 (3.8) years. A total of 14.1% (weighted) initiated smoking, and 6.3% were current smokers at wave 4. Compared with consistently heterosexual identities, coming out as LGB+ (23% vs 13%; odds ratio [OR], 1.72; 95% CI, 1.34-2.20), consistently LGB+ identities (17% vs 13%; OR, 1.45; 95% CI, 1.03-2.04), and other LGB+ patterns (17% vs 13%; OR, 1.47; 95% CI, 1.04-2.08) were positively associated with smoking initiation by wave 4. Compared with consistently heterosexual identities, ORs for smoking initiation were 2.24 (28% vs 13%; 95% CI, 1.72-2.92) for coming out as bisexual, 1.99 (23% vs 13%; 95% CI, 1.20-3.29) for consistently LGB+ with change to/from bisexual, and 2.20 (23% vs 13%; 95% CI, 1.40-3.46) for other LGB+ patterns with change to/from bisexual identity. Current smoking estimates were similar to those for smoking initiation.
Conclusions and relevance: Compared with consistently heterosexual identities, changing sexual identity over follow-up was associated with smoking initiation and current smoking. The risk associated with changing sexual identities was concentrated among participants coming out as bisexual or reporting other changes in their identity to/from being bisexual. More research is needed on mechanisms underlying the association between changing sexual identity and smoking initiation to inform tailored prevention programs and tobacco regulations.