Introduction: Waterpipe use is a significant health concern in low- and middle-income countries like Viet Nam, yet there is a lack of research on factors that may influence use and self-efficacy to quit among adults. Aims: This study examined the relationship between social norms related to waterpipe use and self-efficacy to quit among male waterpipe smokers in Viet Nam. Methods: A cross-sectional survey was conducted with 214 adult male waterpipe smokers enrolled in a large cluster鈥搑andomised controlled trial conducted in a rural province in Viet Nam. Associations between social norms related to waterpipe smoking and the participants鈥� confidence to quit waterpipes were assessed using hierarchical regression models to account for differences among study sites and other covariates. Results: Self-efficacy to quit smoking was positively associated with immediate family members鈥� not minding participants smoking and with extended family's encouragement to quit smoking. Conclusions: The findings suggest the need for a more comprehensive understanding of the functions and characteristics of the social context of waterpipe smoking, including the social networks of waterpipe smokers, to inform effective cessation interventions for waterpipe smokers.
