title: Predictive and External Validity of a Pre-Market Study to Determine the Most Effective Pictorial Health Warning Label Content for Cigarette Packages.
abstract: BACKGROUND
  Studies examining cigarette package pictorial health warning label (HWL) content have primarily used designs that do not allow determination of effectiveness after repeated, naturalistic exposure. This research aimed to determine the predictive and external validity of a pre-market evaluation study of pictorial HWLs.
  
  
  METHODS
  Data were analyzed from: (1) a pre-market convenience sample of 544 adult smokers who participated in field experiments in Mexico City before pictorial HWL implementation (September 2010); and (2) a post-market population-based representative sample of 1765 adult smokers in the Mexican administration of the International Tobacco Control Policy Evaluation Survey after pictorial HWL implementation. Participants in both samples rated six HWLs that appeared on cigarette packs, and also ranked HWLs with four different themes. Mixed effects models were estimated for each sample to assess ratings of relative effectiveness for the six HWLs, and to assess which HWL themes were ranked as the most effective.
  
  
  RESULTS
  Pre- and post-market data showed similar relative ratings across the six HWLs, with the least and most effective HWLs consistently differentiated from other HWLs. Models predicting rankings of HWL themes in post-market sample indicated: (1) pictorial HWLs were ranked as more effective than text-only HWLs; (2) HWLs with both graphic and "lived experience" content outperformed symbolic content; and, (3) testimonial content significantly outperformed didactic content. Pre-market data showed a similar pattern of results, but with fewer statistically significant findings.
  
  
  CONCLUSIONS
  The study suggests well-designed pre-market studies can have predictive and external validity, helping regulators select HWL content.
authors.affiliation: Department of Health Promotion, Education and Behavior, University of South Carolina, Columbia, SC; Center for Regulatory Research on Tobacco Communication, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC; huangl@email.unc.edu.
authors.forename: Li-Ling
authors.initials: LL
authors.lastname: Huang
authors.affiliation: Department of Health Promotion, Education and Behavior, University of South Carolina, Columbia, SC; Department of Tobacco Research, National Institute of Public Health, Cuernavaca, Mexico;
authors.forename: James F
authors.initials: JF
authors.lastname: Thrasher
authors.affiliation: Propel Centre for Population Health Impact, University of Waterloo, Waterloo, ON, Canada;
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Reid
authors.affiliation: School of Public Health and Health Systems, University of Waterloo, Waterloo, ON, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Hammond
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008800:Mexico; D008875:Middle Aged; D011356:Product Labeling / Q000379:methods*; D011640:Public Policy; D000074606:Smoking Prevention; D011795:Surveys and Questionnaires; D062789:Tobacco Products; D055815:Young Adult