title: Progression of Poly-tobacco Product Use Patterns in Adolescents.
abstract: Diverse patterns of adolescent use and poly-use of tobacco products other than conventional cigarettes are emerging. Data characterizing common patterns of youth tobacco product use and typical transitions among patterns may inform tobacco control policy and prevention. This study identified common patterns of use and poly-use of five popular tobacco products (i.e., conventional cigarettes, electronic [e-]cigarettes, hookah, blunts, and cigars) and progression among patterns across time among ninth-graders using latent transition analysis (analyses conducted in 2015).
  
  
  
  Data were from a longitudinal cohort study of ninth-grade students enrolled in ten public high schools in California (N=3,304; 46.6% male; 48.3% Hispanic; mean age, 14.58 [SD=0.40] years), involving a baseline (2013) and 6-month follow-up (2014). Past 6-month any use of the five tobacco products was assessed.
  
  
  
  Poly-use (two or more products) constituted 42% and 50% of tobacco-using teens at baseline and follow-up, respectively. Three common patterns were identified, which reflected successfully greater degrees of low, intermediate, and high diversity of tobacco product use: non-users (baseline prevalence, 0.75; follow-up prevalence, 0.64); e-cigarette/hookah users only (prevalence, 0.21, 0.27); and poly-tobacco product users of all five products (prevalence, 0.04, 0.09). Most typical transitions involved progressing to the next more diverse pattern (non-user→e-cigarette/hookah user [probability=0.13] and e-cigarette/hookah user→poly-tobacco product user [probability=0.19]). Transition from one of the user patterns to non-user status was rare (probability≤0.08).
  
  
  
  Adolescent poly-tobacco use is common. E-cigarette and hookah use may reflect an intermediate pattern of tobacco product use progression along a continuum of poly-product use diversity.
authors.affiliation: Department of Preventive Medicine, University of Southern California, Los Angeles, California. Electronic address: jimihuh@usc.edu.
authors.forename: Jimi
authors.initials: J
authors.lastname: Huh
authors.affiliation: Department of Preventive Medicine, University of Southern California, Los Angeles, California; Department of Psychology, University of Southern California, Los Angeles, California.
authors.forename: Adam M
authors.initials: AM
authors.lastname: Leventhal
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D002140:California / Q000453:epidemiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D012907:Smoking / Q000453:epidemiology / Q000523:psychology*