title: E-cigarette Dual Users, Exclusive Users and Perceptions of Tobacco Products.
abstract: OBJECTIVE
  We examined differences in the characteristics of youth non-users, cigarette-only, e-cigarette-only, and dual e-cigarette and cigarette users.
  
  
  METHODS
  Using weighted, representative data, logistic regression analyses were conducted to examine differences in demographic characteristics and tobacco use behaviors across tobacco usage groups. Multiple linear regression analyses were conducted to examine differences in harm perceptions of various tobacco products and perceived peer use of e-cigarettes by tobacco usage group.
  
  
  RESULTS
  Compared to non-users, dual users were more likely to be white, male, and high school students. Dual users had significantly higher prevalence of current use of all products (except hookah) than e-cigarette-only users, and higher prevalence of current use of snus and hookah than the cigarette-only group. Dual users had significantly lower harm perceptions for all tobacco products except for e-cigarettes and hookah as compared to e-cigarette-only users. Dual users reported higher peer use of cigarettes as compared to both exclusive user groups.
  
  
  CONCLUSIONS
  Findings highlight dual users' higher prevalence of use of most other tobacco products, their lower harm perceptions of most tobacco products compared to e-cigarette-only users, and their higher perceived peer use of cigarettes compared to exclusive users.
authors.affiliation: University of Texas Health Science Center at Houston, School of Public Health, Austin Regional Campus, Austin, TX, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Cooper
authors.affiliation: University of Texas Health Science Center at Houston, School of Public Health, Austin Regional Campus, Austin, TX, USA.
authors.forename: Kathleen R
authors.initials: KR
authors.lastname: Case
authors.affiliation: University of Texas Health Science Center at Houston, School of Public Health, Austin Regional Campus, Austin, TX, USA. alexandra.loukas@austin.utexas.edu.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Loukas
authors.affiliation: University of Texas Health Science Center at Houston, School of Public Health, Austin Regional Campus, Austin, TX, USA.
authors.forename: Melisa R
authors.initials: MR
authors.lastname: Creamer
authors.affiliation: University of Texas at Austin, Department of Kinesiology and Health Education, Austin, TX, USA.
authors.forename: Cheryl L
authors.initials: CL
authors.lastname: Perry
mesh_terms: D000293:Adolescent; D000328:Adult; D066300:Electronic Nicotine Delivery Systems / Q000706:statistics & numerical data*; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D010379:Peer Group; D012907:Smoking / Q000453:epidemiology; D062789:Tobacco Products / Q000706:statistics & numerical data*; D064424:Tobacco Use / Q000453:epidemiology*; D055815:Young Adult