title: Early childhood predictors of early onset of smoking: a birth prospective study.
abstract: OBJECTIVE
  Early onset of smoking is associated with subsequent abuse of other substances and development of negative health outcomes. This study aimed to examine early life predictors of onset of smoking in an Australian young cohort.
  
  
  METHODS
  Data were from the Mater Hospital and University of Queensland Study of Pregnancy (MUSP), a population-based prospective birth cohort study (1981-2012). The present study is based on a cohort of 3714 young adults who self-reported smoking status and age of onset of smoking at the 21-year follow-up. Of these, data were available for 3039 on early childhood factors collected between the baseline and 14-year follow-up of the study.
  
  
  RESULTS
  Of 3714 young adults, 49.6% (49.9% males and 49.3% females) reported having ever smoked cigarettes. For those who had ever smoked, mean and median ages at first smoke were 15.5 and 16.0years, respectively. In multivariate Cox proportional hazard analysis mother's education, change in maternal marital status, maternal cigarette smoking and alcohol consumption, maternal depression and child externalizing when the child was 5years statistically significantly predicted early onset of smoking.
  
  
  CONCLUSIONS
  The data suggest that individuals exposed to personal and environmental risk factors during the early stage of childhood are at increased risk of initiation to cigarette smoking at an earlier age. Identification of the pathways of association between these early life factors and initiation to cigarette smoking may help reduce risk of tobacco smoking in adolescents and its adverse consequences.
authors.affiliation: School of Population Health, University of Queensland, Herston Road, Herston, QLD 4006, Australia. m.hayatbakhsh@uq.edu.au
authors.forename: Reza
authors.initials: R
authors.lastname: Hayatbakhsh
authors.forename: Abdullah A
authors.initials: AA
authors.lastname: Mamun
authors.forename: Gail M
authors.initials: GM
authors.lastname: Williams
authors.forename: Michael J
authors.initials: MJ
authors.lastname: O'Callaghan
authors.forename: Jake M
authors.initials: JM
authors.lastname: Najman
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000428:Alcohol Drinking / Q000453:epidemiology; D001315:Australia / Q000453:epidemiology; D002648:Child; D002653:Child Behavior Disorders / Q000453:epidemiology*; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000453:epidemiology; D017533:Marital Status; D009035:Mothers / Q000523:psychology / Q000706:statistics & numerical data*; D015999:Multivariate Analysis; D011247:Pregnancy; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D012931:Social Environment; D016019:Survival Analysis; D055815:Young Adult
keywords: Age of onset; Cigarette smoking; Early childhood; Predictor