title: A systematic review of longitudinal population-based studies on the predictors of smoking cessation in adolescent and young adult smokers.
abstract: OBJECTIVE
  To describe the determinants of self-initiated smoking cessation of duration of at least 6 months as identified in longitudinal population-based studies of adolescent and young adult smokers.
  
  
  METHODS
  A systematic search of the PubMed and EMBASE databases using smoking, tobacco, cessation, quit and stop as keywords was performed. Limits included articles related to humans, in English, published between January 1984 and August 2010, and study population aged 10-29 years. A total of 4502 titles and 871 abstracts were reviewed independently by 2 and 3 reviewers, respectively. Nine articles were retained for data abstraction. Data on study location, timeframe, duration of follow-up, number of data collection points, sample size, age/grade of participants, number of quitters, smoking status at baseline, definition of cessation, covariates and analytic method were abstracted from each article. The number of studies that reported a statistically significant association between each determinant investigated and cessation were tabulated, from among all studies that assessed the determinant.
  
  
  RESULTS
  Despite heterogeneity in methods across studies, five factors robustly predicted quitting across studies in which the factor was investigated: not having friends who smoke, not having intentions to smoke in the future, resisting peer pressure to smoke, being older at first use of cigarette and having negative beliefs about smoking.
  
  
  CONCLUSIONS
  The literature on longitudinal predictors of cessation in adolescent and young adult smokers is not well developed. Cessation interventions for this population will remain less than optimally effective until there is a solid evidence base on which to develop interventions.
authors.affiliation: Faculty of Medicine, University of Lausanne, Lausanne, Switzerland.
authors.forename: Semanur
authors.initials: S
authors.lastname: Cengelli
authors.forename: Jennifer
authors.initials: J
authors.lastname: O'Loughlin
authors.forename: Beatrice
authors.initials: B
authors.lastname: Lauzon
authors.forename: Jacques
authors.initials: J
authors.lastname: Cornuz
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D019317:Evidence-Based Medicine / Q000379:methods; D006801:Humans; D008137:Longitudinal Studies; D011379:Prognosis; D012907:Smoking / Q000523:psychology*; D016540:Smoking Cessation / Q000379:methods / Q000523:psychology*; D000074606:Smoking Prevention; D055815:Young Adult