Table 1.
Baseline characteristics of students
| Characteristic | Exposure ad (N = 205) |
Neutral ad (N = 192) |
P-value |
|---|---|---|---|
| Age, mean (SD) | 14.0 (1.4) | 14.1 (1.7) | 0.86* |
| Male, n (%) | 83 (40.5) | 76 (39.6) | 0.85 |
| Grade, n (%) | |||
| 7 | 54 (26.3) | 56 (29.2) | 0.43 |
| 8 | 47 (22.9) | 44 (22.9) | |
| 9 | 60 (29.3) | 50 (26.0) | |
| 10 | 23 (11.2) | 14 (7.3) | |
| 11 | 21 (10.2) | 28 (14.6) | |
| Family affluence score, mean (SD)† | 5.5 (1.2) | 5.4 (1.2) | 0.19* |
| Smoking status, n (%) | |||
| Nonsusceptible never smoker | 119 (58.6) | 96 (50.5) | 0.30 |
| Susceptible never smoker | 30 (14.8) | 40 (21.1) | |
| Experimenter | 43 (21.2) | 41 (21.6) | |
| Established smoker | 11 (5.4) | 13 (6.8) | |
| Ice hockey fan, n (%) | |||
| Very much | 67 (32.8) | 64 (33.5) | 0.30 |
| A bit | 55 (27.0) | 60 (31.4) | |
| Not really | 47 (23.0) | 30 (15.7) | |
| No | 35 (17.2) | 37 (19.4) | |
| Test time, n (%)‡ | |||
| Morning | 166 (81.0) | 134 (69.8) | 0.01 |
| Afternoon | 39 (19.0) | 58 (30.2) |
* P-values are based on the Wilcoxon rank sum test for two variables; all other p-values are based on contingency tables for categorical variables.
† Ranges from 1 to 7
‡ Grade 7 and 8 questionnaires were administered during one class period. Grade 9 to 11 questionnaires were administered either in the morning or afternoon.