title: Nondaily, Low-Rate Daily, and High-Rate Daily Smoking in Young Adults: A 17-Year Follow-Up.
abstract: BACKGROUND
  While overall tobacco consumption is declining in many countries, patterns of low-frequency smoking-such as nondaily and low-rate daily smoking-appear to be increasing. We aimed firstly to describe differences in demographic, smoking- and quitting-related characteristics between nondaily and daily smokers in young adults; secondly, to determine the proportion of low-frequency smokers who transition to a higher rate of smoking by age 38 and factors associated with this.
  
  
  METHODS
  We assessed a cohort of individuals born in Dunedin, New Zealand, in 1972-1973, at regular intervals from age 21 to age 38 years. Smokers were categorized as either nondaily, low-rate daily (ie, defined as five or less cigarettes per day) or high-rate daily smokers (six or more cigarettes per day). Descriptive statistics, linear and logistic regression were used.
  
  
  RESULTS
  Nondaily smokers at age 21 tended to self-identify as nonsmokers. Both nondaily smokers and low-rate daily smokers reported higher readiness and confidence in quitting compared to high-rate daily smokers. Around 40% of the age 21 low-rate daily smokers reported smoking daily at age 38, compared to 13% of the nondaily smokers and 4% of the nonsmokers. Nondaily smoking at age 21 was associated with increased odds of being a daily smoker by age 38 (OR: 3.6; 95% CI = 1.7% to 7.8%) compared to nonsmokers.
  
  
  CONCLUSIONS
  Different patterns of smoking are associated with differences in readiness to quit and confidence in quitting ability. For a considerable proportion of smokers, low-frequency smoking in young adulthood develops into daily smoking by adulthood.
  
  
  CONCLUSIONS
  Low-frequency smoking, including nondaily smoking, in early adulthood is a significant risk factor for being a daily smoker in the long-term. Cessation interventions should be tailored to low-frequency smokers, taking into account differences between them and heavier smokers in terms of smoking motivation and quitting-related cognitions.
authors.affiliation: Cancer Society of New Zealand Social and Behavioural Research Unit, Department of Preventive and Social Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand; l.robertson@otago.ac.nz.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Robertson
authors.affiliation: Department of Preventive and Social Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
authors.forename: Ella
authors.initials: E
authors.lastname: Iosua
authors.affiliation: Department of Preventive and Social Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
authors.forename: Rob
authors.initials: R
authors.lastname: McGee
authors.affiliation: Department of Preventive and Social Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Hancox
mesh_terms: D000328:Adult; D005500:Follow-Up Studies; D006801:Humans; D009520:New Zealand / Q000453:epidemiology; D012907:Smoking / Q000453:epidemiology*; D014029:Tobacco Use Disorder / Q000453:epidemiology*; D055815:Young Adult