title: Declining Prevalence of Tobacco Smoking in Vietnam.
abstract: BACKGROUND
  To supplement limited information on tobacco use in Vietnam, data from a nationally-representative population-based survey was used to estimate the prevalence of smoking among 25-64 year-olds.
  
  
  METHODS
  This study included 14,706 participants (53.5% females, response proportion 64%) selected by multi-stage stratified cluster sampling. Information was collected using the World Health Organization STEPwise approach to surveillance of risk factors for non-communicable disease (STEPS) questionnaire. Smoking prevalence was estimated with stratification by age, calendar year, and birth year.
  
  
  RESULTS
  Prevalence of ever-smoking was 74.9% (men) and 2.6% (women). Male ever-smokers commenced smoking at median age of 19.0 (interquartile range [IQR]: 17.0, 21.0) years and smoked median quantities of 10.0 (IQR: 7.0, 20.0) cigarettes/day. Female ever-smokers commenced smoking at median age of 20.0 (IQR: 18.0, 26.0) years and smoked median quantities of 6.0 (IQR: 4.0, 10.0) cigarettes/day. Prevalence has decreased in recent cohorts of men (p = .001), and its inverse association with years of education (p < .001) has strengthened for those born after 1969 (interaction p < .001). At 60 years of age, 53.0% of men who had reached that age were current smokers and they had accumulated median exposures of 39.0 (IQR: 32.0, 42.0) years of smoking and 21.0 (IQR: 11.5, 36.0) pack-years of cigarettes. The proportion of ever-smokers has decreased consistently among successive cohorts of women (p < .001).
  
  
  CONCLUSIONS
  Smoking prevalence is declining in recent cohorts of men, and continues to decline in successive cohorts of women, possibly in response to anti-tobacco initiatives commencing in the 1990s. Low proportions of quitters mean that Vietnamese smokers accumulate high exposures despite moderate quantities of cigarettes smoked per day.
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia; Public Health Faculty, Can Tho University of Medicine and Pharmacy, Can Tho, Vietnam;
authors.forename: Tan Van
authors.initials: TV
authors.lastname: Bui
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia; Leigh.Blizzard@utas.edu.au.
authors.forename: Leigh
authors.initials: L
authors.lastname: Blizzard
authors.affiliation: Medical Services Administration, Ministry of Health of the Socialist Republic of Vietnam, Ha Noi, Vietnam;
authors.forename: Khue Ngoc
authors.initials: KN
authors.lastname: Luong
authors.affiliation: Medical Services Administration, Ministry of Health of the Socialist Republic of Vietnam, Ha Noi, Vietnam;
authors.forename: Ngoc Le Van
authors.initials: Nle V
authors.lastname: Truong
authors.affiliation: Medical Services Administration, Ministry of Health of the Socialist Republic of Vietnam, Ha Noi, Vietnam;
authors.forename: Bao Quoc
authors.initials: BQ
authors.lastname: Tran
authors.affiliation: Medical Services Administration, Ministry of Health of the Socialist Republic of Vietnam, Ha Noi, Vietnam;
authors.forename: Son Thai
authors.initials: ST
authors.lastname: Ha
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia;
authors.forename: Hai Ngoc
authors.initials: HN
authors.lastname: Phung
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia;
authors.forename: Petr
authors.initials: P
authors.lastname: Otahal
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia; Department of Medicine, Southern Clinical School, Monash Medical Centre, Monash University, Clayton, Victoria, Australia.
authors.forename: Srikanth
authors.initials: S
authors.lastname: Velandai
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia;
authors.forename: Mark Raymond
authors.initials: MR
authors.lastname: Nelson
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia;
authors.forename: Thuy Bich
authors.initials: TB
authors.lastname: Au
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia;
authors.forename: Mai Hoang
authors.initials: MH
authors.lastname: Tran
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia;
authors.forename: Quan Long
authors.initials: QL
authors.lastname: Huynh
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia; Department of Medicine, Southern Clinical School, Monash Medical Centre, Monash University, Clayton, Victoria, Australia.
authors.forename: Michele
authors.initials: M
authors.lastname: Callisaya
authors.affiliation: Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia;
authors.forename: Seana
authors.initials: S
authors.lastname: Gall
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology* / Q000639:trends*; D016540:Smoking Cessation; D011795:Surveys and Questionnaires; D064424:Tobacco Use / Q000453:epidemiology / Q000639:trends; D014744:Vietnam / Q000453:epidemiology