Transitions in tobacco product use involving combustible cigarettes, heated tobacco products and electronic cigarettes among 7 million South Korean adults: a prospective cohort study

Background We investigated the roles of heated tobacco products (HTPs) and electronic cigarettes (ECs) in combustible cigarette (CCs) smoking initiation, relapse and cessation, as well as in all tobacco product discontinuation and transition of dual and triple use of CCs, HTPs and ECs. Method Researchers analysed data from Korea National Health Insurance Service including 7 260 125 Korean adults who participated in three biennial health screenings between 2019 and 2023. Multivariable logistic regression analyses were performed to investigate the associations of HTPs and ECs use with initiation, relapse and cessation of CCs smoking and discontinuing all tobacco products, and transition probabilities were estimated to characterise changes in tobacco-use patterns. Results Compared with participants who reported never using, those who reported current HTPs and ECs use had higher odds of initiation, relapse and cessation of CCs smoking, but lower odds of discontinuing all tobacco products. Among participants who reported dual use of CCs and HTPs, more than 70% transitioned to CCs’ use. Complete cessation of all tobacco products was less common among dual and triple users of HTPs, ECs and CCs than among exclusive CC users. Conclusion Although HTPs and ECs use was associated with increased CCs smoking cessation, these products drive higher rates of CC initiation and relapse and lower rates of complete tobacco cessation. Most users of multiple tobacco products revert to CCs smoking and are less likely to successfully quit all tobacco use. The net public health impact of these evolving tobacco use patterns in Korea remains uncertain.