Alcohol dependence trajectories and smoking cessation among Korean men who smoke: A secondary data analysis from the Korean longitudinal study of aging dataset

TL;DR

This study shows that long-term patterns of alcohol dependence in Korean men are linked to lower chances of quitting smoking, especially in younger individuals.

Contribution

The study identifies distinct alcohol dependence trajectories and their impact on smoking cessation among Korean men using longitudinal data.

Findings

Three alcohol dependence trajectories were identified: stable low, decreasing, and increasing.

Men with increasing or decreasing alcohol dependence were less likely to quit smoking than those with stable low dependence.

Current smokers were more likely to belong to the increasing alcohol dependence trajectory.

Abstract

Alcohol dependence may hinder smoking cessation, yet few studies have examined how long-term patterns of alcohol use influence quit outcomes. This study assessed how alcohol dependence trajectories affect smoking cessation among Korean men who smoke.

We performed a secondary analysis using waves 1–7 (2006–2018) of the Korean Longitudinal Study of Aging (KLoSA). Latent class growth analysis (LCGA) identified alcohol dependence trajectories among 2356 men aged ≥45 years who participated in at least three consecutive waves. Multinomial logistic regression (n=1959) was used to assess predictors of trajectory class membership, and Cox proportional hazards models (n=1122) were used to evaluate the association between class membership and smoking cessation. Statistical significance was set at a two-sided p<0.05.

Three alcohol dependence trajectories were identified: stable low (80.7%), decreasing (14.3%), and increasing (5.0%). Participants in the decreasing (adjusted hazard ratio, AHR=0.77; 95% CI: 0.63–0.95) and increasing (AHR=0.60; 95% CI: 0.42–0.86) groups were less likely to quit smoking than the stable low group. Multinomial regression showed that, compared to non-smokers, both former smokers (AOR=1.83; 95% CI: 1.24–2.70) and current smokers (AOR=2.23; 95% CI: 1.60–3.09) were associated with higher odds of belonging to the decreasing trajectory. Only current smoking was significantly associated with the increasing trajectory (AOR=2.28; 95% CI: 1.36–3.84). In stratified analyses, the inverse association between increasing trajectory and quitting was significant only in those aged 45–54 years. Sensitivity analyses using weighted and complete-case data confirmed the robustness of the findings.

Alcohol dependence trajectories were significantly associated with smoking cessation outcomes, especially among younger individuals. Smoking status was also a significant predictor of trajectory class membership, with current smokers more likely to belong to the increasing trajectory. Integrated interventions addressing both behaviors may improve cessation outcomes in high-risk groups.

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