Table 2 Proportion of participants who quit smoking (biochemically confirmed and self-reported) and proportion who reduced the number of cigarettes smoked per day
VBA only | VBA + lung age | VBA + exhaled CO | VBA + lung age | VBA + exhaled CO | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Total | n (%) | Total | n (%) | Total | n (%) | RR (95% CI) | p-value | RR (95% CI) | p-value | |
Quit smoking (biochemically confirmed) | ||||||||||
At 4wksa | 450 | 8 (1.8) | 449 | 7 (1.6) | 442 | 8 (1.8) | 0.90 (0.35–2.27)b | 0.792 | 1.04 (0.44–2.44)b | 0.920 |
At 12wks | 445 | 8 (1.8) | 447 | 6 (1.3) | 440 | 10 (2.3) | 0.78 (0.32–1.89) | 0.578 | 1.29 (0.65–2.57) | 0.463 |
At 26wks | 435 | 1 (0.2) | 438 | 7 (1.6) | 428 | 3 (0.7) | 6.98 (1.09–44.54) | 0.040 | 3.11 (0.28–35.10) | 0.358 |
Quit smoking (self-reported) | ||||||||||
At 4wks | 450 | 8 (1.8) | 449 | 9 (2.0) | 442 | 15 (3.4) | 1.15 (0.51–2.59) | 0.731 | 1.95 (0.92–4.10) | 0.080 |
At 12wks | 445 | 11 (2.4) | 447 | 11 (2.4) | 439 | 18 (4.1) | 1.02 (0.45–2.30) | 0.970 | 1.69 (0.73–3.91) | 0.218 |
At 26wks | 435 | 11 (2.5) | 437 | 17 (3.9) | 428 | 15 (3.5) | 1.58 (0.74–3.38) | 0.243 | 1.41 (0.65–3.08) | 0.391 |
Reduction in cpd | ||||||||||
At 4wks | 389 | 110 (28.3) | 386 | 141 (36.5) | 383 | 132 (34.5) | 1.30 (1.10–1.54) | 0.002 | 1.23 (1.03–1.49) | 0.026 |
At 12wks | 385 | 143 (37.1) | 380 | 160 (42.1) | 376 | 152 (40.4) | 1.15 (1.00–1.32) | 0.048 | 1.11 (0.93–1.32) | 0.240 |
At 26wks | 372 | 172 (46.2) | 365 | 173 (47.4) | 366 | 182 (49.7) | 1.03 (0.94–1.14) | 0.507 | 1.09 (0.95–1.26) | 0.225 |