Treatment effects on number of participants achieving smoking cessation at six weeks
| Control n (%) | Active n (%) | RR (95% CI) | p Value | |
|---|---|---|---|---|
| *Assumes all participants with missing smoking status were smoking. | ||||
| †Assumes all participants with missing smoking status were not smoking. | ||||
| ‡Assumes participants with missing smoking status in the control group were not smoking but participants with missing smoking status in the active group were smoking. | ||||
| §Assumes the proportion of non-confirmed quitters in the sample assessed for salivary cotinine (that is, 23/49 = 0.47) was the same for the whole trial population. | ||||
| ¶Assumes the proportion of non-confirmed quitters for the sample selected for salivary cotinine (including those selected for test but who did not attend, 23/125 = 0.18) was the same for the whole trial population. | ||||
| CI, confidence interval; RR, relative risk. | ||||
| Main analysis | ||||
| Missing status assumed smoking | 109 (12.8) | 239 (28.1) | 2.20 (1.79 to 2.70) | <0.0001 |
| Sensitivity analyses | ||||
| Missing status: assumed not smoking† | 144 (16.9) | 285 (33.5) | 1.98 (1.66 to 2.36) | <0.0001 |
| Missing status: assumed not smoking in control group only‡ | 144 (16.9) | 239 (28.1) | 1.66 (1.38 to 2.00) | <0.0001 |
| Adjustment for salivary cotinine verification§ | 51 (6.2) | 112 (13.9) | 2.23 (1.62 to 3.06) | <0.0001 |
| Adjustment for salivary cotinine verification and test attendance¶ | 20 (2.4) | 44 (5.5) | 2.23 (1.32 to 3.75) | 0.002 |
| Restriction to only those with salivary cotinine verification | 6 (0.7) | 17 (2.0) | 2.84 (1.12 to 7.16) | 0.02 |