Table 1

Multivariate and univariate results for the effects of graphic health warning levels and plain packaging on adolescent smokers from the USA, Spain and France

Multivariate analysis of covariance resultsUnivariate F-values
Independent variablesWilks' λF-valueCigarette cravingEvoked fearPack feelingsQuit thoughts
Main effects
All countries
 Graphic level (GL)0.8811.60***21.55***38.14***17.18***10.83**
 Plain pack (PP)0.986.03***8.58***5.42**10.06***0.21
 Country (C)0.974.40***9.24***8.99***1.662.48*
USA
 GL0.922.52***5.88***5.83***4.18***3.86***
 PP0.945.58***4.03**5.40**3.94**0.52
Spain
 GL0.864.10***8.44***10.87***3.11**2.00
 PP0.990.902.611.351.010.20
France
 GL0.758.77***9.59***28.44***17.92***5.51***
 PP0.972.42**2.190.176.33**0.03
Interaction effects
All countries
 GL×C0.961.64**1.311.76*3.83***0.25
 GL×PP0.990.700.790.100.300.68
 PP×C0.991.170.031.060.520.65
 GL×C×PP0.971.51**1.95*1.562.04*0.33
USA
 GL×PP0.980.670.620.591.140.74
Spain
 GL×PP0.951.450.470.432.59**1.60
France
 GL×PP0.941.78**3.61**2.46*0.930.65
  • ***p≤0.01; **p≤0.05; *p≤0.10. All values are adjusted for age, gender, and brand familiarity as covariates.