Factors Associated with the Dual Use of Electronic Cigarettes and Cigarettes among Thai Undergraduate Students Who Smoked Cigarettes.

This study proposed to identify factors associated with the dual use of electronic cigarettes (e-cigarettes) and cigarettes among undergraduate students who smoked cigarettes. This cross-sectional study employed a self-administered, anonymous online questionnaires to collect information from undergraduate smokers in northern Thailand. Of the 494 participants, 82.8% were dual users of e-cigarettes and cigarettes. The two main reasons for using e-cigarettes were an absence of cigarette smoke odor (76.8%) and availability of flavors (70.7%). Undergraduate smokers who initiated smoking at ≥18 years old were more likely to be dual users than those who initiated smoking at younger age (adjusted odds ratio [aOR]: 2.79, 95% confidence intervals [CI]: 1.32-5.89, p = 0.007). Undergraduate smokers who smoked ≥11 cigarettes daily were more likely to be dual users than those who smoked less (aOR: 2.64, 95% CI: 1.52-4.61, p = 0.001). Conversely, undergraduate smokers who had attempted to quit during the past year were less likely to be dual users (aOR: 0.26, 95% CI: 0.12-0.56, p = 0.001). In conclusion, dual use of e-cigarettes and cigarettes among undergraduate smokers was associated with older age at cigarette smoking initiation, a higher number of cigarettes smoked daily, and having no past year's cigarette quit attempts.