Ex-Smokers Re-Smoking: A Primary Determinant of the Trends in Cigarette Smoking among US Adolescents-Analysis of Behavior Transition Using the PEDS Method and Cross-Sectional Data

The declining trends in US adolescent smoking slowed down since 2003. Restoring the declining momentum requires further understanding of the dynamics of smoking behavior. We tested a three-stage model (never-smokers NS, current smokers CS and ex-smokers XS) using the probability discrete event system (PDES) and Mason's formula for signal flow and data from the 1991-2008 Monitor the Future. Annual reductions in CS during 1997-2003 were 1.53%, 2.18% and 2.02% for students in grades 8, 10 and 12 respectively; the same reduction rates in 2003-08 were reduced to 0.68%, 0.88% and 0.80%. Transitional probabilities estimated using the PDES method indicated that when passing through grades 8-12, 9.6% of youth initiated smoking, of whom 6.2% progressed to CS and 3.4% directly progressed to XS; among all CS youth, 16.3% quitted and among all XS youth, 12.4% re-smoked to become CS. Among every 100 NS youth, 6.8 new CS youth were added. Substantial changes in smoking transition during 1997-2003 included 33.1% increases in transition from CS to XS, 13.7% increases in probability for XS remaining XS, and 65.3% declines in transitions from XS to CS. From 2003 to 2008, the transition from XS to CS increased 145.6% and XS remaining as XS reduced 18.9%. Study findings imply that ex-smokers re-smoking are more important than current smokers quitting and other steps of transition in determining the trends in US adolescent smoking. Prevention effort should be directed more toward preventing young ex-smokers from re-smoking in order to restore the declining momentum of adolescent smoking.