Introduction:
Presently, smokers use both cigarettes and e-cigarettes (dual user smokers). The availability of electronic cigarettes (e-cigarettes) has profoundly changed the tobacco product landscape. E-cigarettes were used by smokers has been growing rapidly. It is important to observe and assess patterns in the use of e-cigarettes.

Objectives:
The purpose of this study was to understand how dual users differ in terms of demographics and nicotine dependence. The characteristic of dual user smokers who called Thailand National Quitline (TNQ) were examined.

Methods:
This study used an in cross-sectional research design. Data were obtained from 948 smokers who had received smoking cessation intervention from TNQ. Secondary data from the database of smokers who called TNQ from January 2016 to December 2018 were used. Research instruments consisted of demographic data and smoking-related information such as nicotine dependence, confidence to quit and quit smoking questionnaire. The acquired data were analyzed by using descriptive statistics.

Results:
Demographic data revealed that the subjects had an age range from 14-65 years-old. Almost half of them had an age range from 15-24 years (49.05%). The majority of them were male (90.51%). Compared to general smokers, dual user smokers were younger. Around one-third of them were the student. They have more education, report a history of psychiatric co-morbidity, hypertension, and respiratory disease. Smoking-related information revealed that most of them smoked daily (94.94%), and one-thirds smoked more than 20 cigarettes per day. Half of them smoked within 5 minutes after waking (61.39%) and smoked when sick (58.12%). Half of them reported quit attempt in the previous year (55.70%), they used to cut down technique when the stopped smoking (66.56%), Family was a motivation to cessation. In addition, they report confidence to quit at a high level.

Conclusion(s):
The results revealed that dual users are supplementing their smoking with e-cigarette use. Further research needs to compare the characteristics of single users and dual users.