Early childhood predictors of early onset of smoking: A birth prospective study

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 493% females) reported having ever smoked cigarettes. For those who had ever smoked, mean and median ages at first smoke were 15.5 and 16.0 years, 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 5 years 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. (C) 2013 Elsevier Ltd. All rights reserved.