Primary and secondary outcomes (number of imputations=10)
| Control (%) | Intervention (%) | Relative risk (95% CI) | P value (two-sided) | |
| Self-reported quit attempt (lasted 24 hours) | 52.8 | 59.0 | 1.12 (0.97 to 1.28) | 0.120 |
| Self-reported 10-day continuous abstinence | 20.8 | 32.2 | 1.55 (1.19 to 2.03) | <0.001 |
| Self-reported 1-month continuous abstinence* | 16.9 | 28.5 | 1.68 (1.25 to 2.28) | <0.001 |
| Self-reported 3-month continuous abstinence | 10.2 | 23.8 | 2.08 (1.38 to 3.18) | <0.001 |
| Self-reported 6-month continuous abstinence | 4.8 | 10.2 | 2.02 (1.08 to 3.81) | 0.024 |
*Primary outcome.