Self-reported abstinence (intention to treat analysis)
| Control (%) | Intervention (%) | Relative risk (95% CI) | P value (two-sided) | |
| Lost to follow-up treated as smokers | ||||
| Self-reported 10-day continuous abstinence | 19.0 | 30.9 | 1.63 (1.23 to 2.17) | <0.001 |
| Self-reported 1-month continuous abstinence | 13.2 | 26.0 | 1.97 (1.41 to 2.79) | <0.001 |
| Self-reported 3-month continuous abstinence | 7.9 | 17.3 | 2.19 (1.39 to 3.46) | <0.001 |
| Self-reported 6-month continuous abstinence | 3.2 | 7.3 | 2.27 (1.09 to 4.86) | 0.026 |
| Lost to follow-up excluded | ||||
| Self-reported 10-day continuous abstinence | 19.9 | 31.8 | 1.59 (1.21 to 2.12) | <0.001 |
| Self-reported 1-month continuous abstinence | 14.2 | 27.4 | 1.92 (1.39 to 2.66) | <0.001 |
| Self-reported 3-month continuous abstinence | 8.9 | 18.9 | 2.13 (1.36 to 3.36) | 0.001 |
| Self-reported 6-month continuous abstinence | 3.8 | 8.5 | 2.23 (1.08 to 4.77) | 0.029 |