Table 3

For health messages introduced post plain packaging, unadjusted proportion (95% CI) of students agreeing or strongly agreeing that smoking causes these diseases by year and smoking status among students who had seen a cigarette pack within the previous 6 months (weighted data)

χ2 Statistic and p values*
Years GHW in circulationNSNS
% (95% CI)
SNS
% (95% CI)
ES
% (95% CI)
CS
% (95% CI)
Total
% (95% CI)
YearSmoking statusInteraction of year and smoking status
2011 (weighted N)(2150)(349)(830)(405)(3733)
2013 (weighted N)(2558)(253)(653)(286)(3851)
Diseases of the gums
 2011 (%)Message from 1/8/201388 (86 to 89)84 (81 to 88)89 (87 to 91)86 (82 to 89)87 (86 to 89)χ2(1)=0.42,
p=0.52
χ2(3)=13.86, p=0.003χ2(3)=3.72, p=0.29
 2013 (%)87 (85 to 88)84 (80 to 87)89 (87 to 91)85 (81 to 89)87 (85 to 88)
Kidney disease
 2011 (%)Message from 1/8/201378 (76 to 80)77 (73 to 81)78 (76 to 81)75 (71 to 79)78 (76 to 79)χ2(1)=1.77,
p=0.18
χ2(3)=6.51, p=0.09χ2(3)=2.52, p=0.47
 2013 (%)80 (78 to 83)79 (75 to 83)80 (78 to 83)77 (73 to 81)80 (78 to 82)
Bladder cancer
 2011 (%)Message from 1/8/201363 (61 to 65)61 (57 to 66)64 (60 to 67)63 (58 to 68)63 (61 to 65)χ2(1)=9.57, p=0.002χ2(3)=2.98, p=0.40χ2(3)=4.13, p=0.25
 2013 (%)69 (65 to 72)67 (63 to 71)69 (66 to 73)69 (64 to 73)69 (66 to 71)
  • In total, 104 students had missing data on the smoking status variable and were excluded from analyses. Missing data on the different items over the two surveys ranged from 6 to 20.

  • *Analyses adjusted for covariates of sex, age, school education sector, state and smoking status.

  • CS, smoking in past week/established smokers; ES, experimental smokers; NSNS, non-susceptible never-smokers; SNS, susceptible never-smokers.