title: Effect of warning statements in e-cigarette advertisements: an experiment with young adults in the United States.
abstract: OBJECTIVE
  This on-line experiment examined whether the addition of ingredient- or industry-themed warning statements in television advertisements for e-cigarettes would affect young adults' craving for and risk perceptions of e-cigarettes and combustible cigarettes, as well as intent to purchase e-cigarettes.
  
  
  METHODS
  Advertisements for two leading e-cigarette brands were edited to contain a warning statement about product ingredients or about the tobacco industry. Participants were assigned randomly to one of eight treatments or one of two brand-specific control conditions without any warning statement.
  
  
  METHODS
  Young adults (n=900, aged 18-34 years) in a web panel were recruited from three groups: recent e-cigarette users, current smokers who used combustible cigarettes exclusively and non-users of either product.
  
  
  METHODS
  Craving and risk perceptions (addictiveness, harmful to health in general, harmful to others) were measured separately for e-cigarettes and combustible cigarettes. The Juster scale measured intention to purchase e-cigarettes.
  
  
  RESULTS
  Exposure to both types of warnings was associated with lower craving for e-cigarettes among e-cigarette users and smokers who experienced any craving (P<0.01) and lower intention to purchase among all participants (P<0.001). Only exposure to ingredient-themed warnings was associated with lower craving for combustible cigarettes (P<0.05). Participants who saw industry-themed warnings reported greater perceptions of general harm (P<0.001), but also rated e-cigarettes as less addictive than the control conditions (P<0.05).
  
  
  CONCLUSIONS
  The addition of ingredient- or industry-themed warning statements to e-cigarette television advertising similarly reduces craving and purchase intent for e-cigarettes, but has inconsistent effects on perceived risks.
authors.affiliation: Stanford Prevention Research Center, School of Medicine, Stanford University, Palo Alto, CA, USA.
authors.forename: Ashley
authors.initials: A
authors.lastname: Sanders-Jackson
authors.affiliation: Stanford Prevention Research Center, School of Medicine, Stanford University, Palo Alto, CA, USA.
authors.forename: Nina C
authors.initials: NC
authors.lastname: Schleicher
authors.affiliation: Stanford Prevention Research Center, School of Medicine, Stanford University, Palo Alto, CA, USA.|Kaiser Permanente Center for Health Research, Portland, OR, USA.
authors.forename: Stephen P
authors.identifier: http://orcid.org/0000-0002-1327-9341
authors.initials: SP
authors.lastname: Fortmann
authors.affiliation: Stanford Prevention Research Center, School of Medicine, Stanford University, Palo Alto, CA, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Henriksen
mesh_terms: D000293:Adolescent; D000328:Adult; D000329:Advertising; D001294:Attitude to Health; D066249:Craving; D066300:Electronic Nicotine Delivery Systems / Q000523:psychology*; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D033182:Intention; D010465:Perception; D018570:Risk Assessment; D012907:Smoking / Q000523:psychology; D013690:Television; D014481:United States; D055815:Young Adult
keywords: Advertising; craving; e-cigarettes; intention to purchase; perceived risk; warning labels