Outcome | Intervention group | Control group | RR (95% CI) | χ2 p value |
No (%) | No (%) | |||
4 weeks | ||||
Self-reported quitting* | 26 (25.7) | 12 (12.8) | 2.02 (1.08 to 3.76) | 0.02 |
Self-reported quitting† | 26 (25.5) | 12 (12.2) | 2.08 (1.11 to 3.89) | 0.02 |
6 months | ||||
Primary outcome for the main trial: | ||||
Self-reported no smoking in last 7 days and salivary cotinine <7 ng/ml* | 8 (8.5) | 6 (6.7) | 1.28 (0.46 to 3.53) | 0.6 |
Self-reported no smoking in last 7 days and salivary cotinine <7 ng/ml† | 8 (7.8) | 6 (6.1) | 1.28 (0.46 to 3.56) | 0.6 |
Secondary outcomes—smoking: | ||||
Self-reported no smoking in last 7 days* | 15 (15.5) | 19 (20.4) | 0.76 (0.41 to 1.40) | 0.3 |
Self-reported 28 days continuous abstinence* | 14 (14.4) | 17 (18.1) | 0.80 (0.42 to 1.53) | 0.4 |
Secondary outcome—adverse: | ||||
Self-reported involvement in vehicle crashes* | 1 (1.0) | 4 (4.3) | 0.24 (0.03 to 2.11) | 0.2 |
Pain in thumb while texting* | 0 (0.0) | 1 (1.1) | – | 0.3 |
*Missing data excluded. †Missing data treated as smokers.