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 circulation | NSNS % (95% CI) | SNS % (95% CI) | ES % (95% CI) | CS % (95% CI) | Total % (95% CI) | Year | Smoking status | Interaction 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 1/8/2013 | 88 (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=0.003 | χ2(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 1/8/2013 | 78 (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=0.09 | χ2(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 1/8/2013 | 63 (61 to 65) | 61 (57 to 66) | 64 (60 to 67) | 63 (58 to 68) | 63 (61 to 65) | χ2(1)=9.57, p=0.002 | χ2(3)=2.98, p=0.40 | χ2(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.