Sex-specific trends in patterns of tobacco and nicotine use among young people in Denmark from 2020 to 2023: A multigroup latent class analysis

Introduction: Research on tobacco and nicotine use patterns lacks insights into the diverse nature of tobacco and nicotine use across sexes, particularly how use patterns cluster differently over time between males and females. This study examines the changing patterns of tobacco and nicotine use among Danish young people from 2020 to 2023, focusing on sex differences. Method: Data were collected from five waves of repeated cross-sectional surveys among individuals aged 15-29 (n = 45,473). Multi-group latent class analysis (LCA) was applied to explore differences in tobacco and nicotine use patterns over time and across sexes, using cigarettes, e-cigarettes, smokeless tobacco (SLT), and hookah as indicators. Results: Three latent classes were identified for males and females, with slight differences. For males, these classes were 1) Poly-tobacco use (POLY), 2) Daily SLT use and occasional cigarette use, and 3) Never and non-current use. For females, these classes were 1) POLY, 2) SLT and occasional cigarette use, and 3) Never and non-current use. These classes were consistently identified across the five waves, but the item-response probabilities within each class changed, indicating dynamic product use trends. Males demonstrated higher probabilities of daily use of multiple products, while females showed higher probabilities of occasional use. Notably, e-cigarette use and daily SLT use probabilities increased within the POLY class over time, while cigarette use probabilities declined. For example, the probabilities of daily e-cigarette use increased from 0.14 in 2020 to 0.27 in 2023 among males and from 0.11 in 2020 to 0.23 among females. These findings suggest that new nicotine products, particularly ecigarettes, significantly contribute to the increasing trend of poly-tobacco use. Conclusion: Our study highlights the importance of sex-responsive tobacco control strategies that address males' and females' unique patterns and preferences. Future research should continue to explore these sex differences to inform effective tobacco control policies.