title: Impact of differing definitions of dual tobacco use: implications for studying dual use and a call for operational definitions.
abstract: BACKGROUND
  Concomitant use of two forms of tobacco is an increasing public health concern, yet there is little consensus regarding a consistent definition of so-called "dual use." We defined dual use as cigarette and smokeless tobacco (ST) consumption with either product used daily or nondaily.
  
  
  METHODS
  We analyzed a cohort of 36,013 Air Force recruits. We categorized dual tobacco use across 2 dimensions, type of tobacco products (cigarettes, ST, or others), and the frequency of use (daily vs. nondaily). We determined how varying the definition impacted the prevalence estimates and evaluated the prevalence estimate based on our recommended definition of dual use. Multivariate logistic regression analysis was used to evaluate the risk profile of dual users of ST and cigarettes versus mono users of ST and mono users of cigarettes.
  
  
  RESULTS
  Varying definitions of dual use vary prevalence estimates 50-fold (0.5%-25.3%). Including only ST and cigarettes narrows the prevalence estimate to less than 4-fold (2.0%-9.7%). Dual users are more likely to be young Caucasian males, with lower education, and from families with relatively higher incomes. Compared with mono users, dual users of cigarettes and ST have a distinct pattern of risk profiles.
  
  
  CONCLUSIONS
  Depending on the definition of dual use, markedly different prevalence and risk profiles are observed. Dual users of ST and cigarettes are a unique group of tobacco users. We propose a common definition of dual use to advance our understanding of this unique group.
authors: Department of Preventive Medicine, University of Tennessee Health Science Center, 66 North Pauline, Memphis, TN 38105, USA. bob.klesges@stjude.org
authors: Robert C
authors: RC
authors: Klesges
authors: Jon O
authors: JO
authors: Ebbert
authors: Glen D
authors: GD
authors: Morgan
authors: Deborah
authors: D
authors: Sherrill-Mittleman
authors: Taghrid
authors: T
authors: Asfar
authors: Wayne G
authors: WG
authors: Talcott
authors: Margaret
authors: M
authors: Debon
mesh_terms: D000293:Adolescent; D057229:Alcoholics; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008889:Military Personnel; D015995:Prevalence; D012309:Risk-Taking; D012907:Smoking / Q000453:epidemiology*; D009626:Terminology as Topic; D020340:Tobacco Use Cessation; D014030:Tobacco, Smokeless; D014481:United States / Q000453:epidemiology; D055815:Young Adult