χ2 statistic and p value‡ | ||||
---|---|---|---|---|
Some cigarette brands are: | 2011 % (95% CI) | 2013 % (95%CI) | Year | Interaction: year and smoking status |
(Weighted N) | (3738) | (3856) | ||
Easier to smoke than others | ||||
Agree | 28% (26% to 31%) | 26% (23% to 28%) | χ2 (2)=14.83, p<0.001 | χ2 (6)=2.33, p=0.89 |
Disagree | 22% (20% to 24%) | 19% (17% to 20%) | ||
Don't know | 49% (47% to 52%) | 56% (53% to 59%) | ||
More addictive than others | ||||
Agree | 33% (32% to 35%) | 34% (32% to 36%) | χ2 (2)=6.68, p=0.04 | χ2 (6)=19.66, p=0.003 |
Disagree | 20% (19% to 22%) | 18% (16% to 19%) | ||
Don't know | 46% (44% to 49%) | 49% (46% to 51%) | ||
Easier to quit than others | ||||
Agree | 18% (16% to 19%) | 16% (14% to 17%) | χ2 (2)=1.47, p=0.48 | NA |
Disagree | 32% (30% to 34%) | 31% (29% to 33%) | ||
Don't know | 51% (48% to 53%) | 54% (51% to 56%) | ||
Contain more harmful substances | ||||
Agree | 37% (35% to 39%) | 38% (36% to 41%) | χ2 (2)=10.63, p=0.005 | χ2 (6)=6.64, p=0.36 |
Disagree | 20% (18% to 22%) | 17% (15% to 18%) | ||
Don't know | 43% (41% to 45%) | 45% (43% to 47%) | ||
Have better looking packs than others | ||||
Agree | 43% (40% to 44%) | 25% (23% to 28%) | χ2 (2)=117.41, p<0.001 | χ2 (6)=28.51, p<0.001 |
Disagree | 25% (24% to 27%) | 36% (34% to 38%) | ||
Don't know | 32% (30% to 35%) | 39% (36% to 41%) |
Ninety-four students had missing data on the smoking status variable and were excluded from analyses. Students with missing data on a statement excluded for that analysis. The number of students with missing data for the different variables ranged from 129 to 161.
*Agree or strongly agree combined.
†Disagree or strongly disagree combined.
‡Analyses included smoking status, sex, age, school denomination and state as covariates. NA, not applicable: as there was no main effect of year, the interaction between year and smoking status was not investigated.