Intersectional Smoking Trajectories Across the Life Course in the United Kingdom: A Longitudinal MAIHDA Study

• In Event: Medical Sociology Section Roundtables
  In Refereed Roundtable (90 minute): Table 7. The Life Course and Health I

Abstract

Background: Inequalities in smoking are well documented across gender, ethnicity and socioeconomic position, yet little is known about how these dimensions combine intersectionally across the life course and generational cohorts.
Methods: We apply a longitudinal MAIHDA (Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy) framework to examine age-specific intersectional smoking trajectories in the United Kingdom. Using data from 76,832 individuals aged 16 years and older in the UK Household Longitudinal Study (2009–2024), individuals were nested within 353 intersectional strata defined by sex, ethnicity, education and generation. Smoking status (current smoker vs non-smoker) was modelled using multilevel regression to estimate life course trajectories and quantify the proportion of variance in smoking attributable to between-strata heterogeneity.
Results: Smoking followed a non-linear age trajectory, generally declining across adulthood, with substantial differences in longitudinal patterns across intersectional strata. Educational inequalities were persistent, with higher smoking probabilities among individuals with lower qualifications throughout the life course, and were particularly pronounced in early adulthood before narrowing with age. South Asian, Other Asian and Black populations showed lower smoking levels than White individuals. Generational patterns were strongly age-dependent: Generation Y showed the highest smoking probabilities in early adulthood, Generation Z exhibited increasing smoking trajectories, and the Silent Generation had comparatively lower smoking probabilities. A meaningful proportion of variance was attributable to intersectional strata, much of which was explained by additive effects, though residual multiplicative intersectional variance remained. Intersectional inequalities were smaller in midlife and larger in both early and later adulthood, with some divergence persisting at older ages.
Conclusion: These findings highlight that smoking inequalities evolve across the life course and become increasingly stratified in later life. Intersectionally informed and age-sensitive tobacco control strategies may therefore be necessary to address persistent disparities.

Authors

• Vladimir Jolidon, Harvard T.H . Chan School of Public Health

• Ichiro Kawachi

• Andrew Bell

• Daniel Holman