Prevalence of cigarette and e-cigarette dual use and associated factors among people who smoke in China aged 20-69 years.

BACKGROUND AND AIMS: Evidence on the dual use profile of electronic cigarettes (e-cigarettes) and cigarettes remains limited, especially for the adult population. This study aimed to assess the prevalence and associated factors of lifetime dual use among adults who smoke in China. METHODS: The nationally representative survey of the China Health Literacy Survey (CHLS) was conducted in 2018. Participants were recruited from 31 provinces in the Mainland of China (n=21,582). Dual use was defined as self-reported ever use of both cigarettes and e-cigarettes. Multivariate logistic regression models with weights (accounting for study design, non-response rate and post hoc stratification) were used to identify the associated factors of dual use, shown in adjusted odds ratios (aOR) and 95% confidence intervals (CI). RESULTS: The prevalence of lifetime dual use of cigarettes and e-cigarettes was 0.82% in China, 2.95% among those who ever smoked, and 3.01% among those who currently smoked. The dual use was consistently more prevalent in urban areas than rural areas and decreased with age. In the adjusted logistic model, dual use was associated with younger age, living in urban areas, single status, high educational level, high income, poor self-reported health status, nicotine dependence, and other smoking-related factors. Withdrawal symptoms were more prevalent among those who used both cigarettes and e-cigarettes compared with those who exclusively smoked cigarettes, including the urge to smoke, hard to concentrate, quick temper, increased appetite, weight gain, involuntary hand tremor, and sleepiness (P<0.05). CONCLUSION: Although the prevalence of lifetime dual use is low, the absolute number of affected individuals in China is substantial. Our study identified key risk factors associated with lifetime dual use, providing critical evidence to inform targeted interventions for at-risk populations and guide the development of tailored tobacco control strategies.