Table 4.
Adjusted risk of lung cancer in heavy former vs never smokers*
| YSQ category | Person-exams | Lung cancers | Adjustedhazard ratio† (95% CI) | P‡ |
|---|---|---|---|---|
| Combined cohorts | ||||
| <5 | 2828 | 27 | 12.12 (6.94 to 21.17) | <.001 |
| 5 to <10 | 2301 | 27 | 11.77 (6.78 to 20.45) | <.001 |
| 10 to <15 | 1564 | 15 | 7.81 (3.98 to 15.33) | <.001 |
| 15 to <25 | 2332 | 22 | 5.88 (3.19 to 10.83) | <.001 |
| 25+ | 1459 | 12 | 3.85 (1.80 to 8.26) | <.001 |
| Never smokers (referent) | 30 847 | 25 | 1.00 | − |
| Original cohort | ||||
| <5 | 1882 | 13 | 11.60 (5.47 to 24.61) | <.001 |
| 5 to <10 | 1409 | 11 | 10.46 (4.67 to 23.42) | <.001 |
| 10 to <15 | 951 | 9 | 10.30 (4.18 to 25.41) | <.001 |
| 15 to <25 | 1280 | 12 | 7.81 (3.44 to 17.74) | <.001 |
| 25+ | 770 | 7 | 5.96 (2.15 to 16.54) | <.001 |
| Never smokers (referent) | 20 384 | 13 | 1.00 | − |
| Offspring cohort | ||||
| <5 | 946 | 14 | 12.32 (5.38 to 28.20) | <.001 |
| 5 to <10 | 892 | 16 | 12.33 (5.64 to 26.96) | <.001 |
| 10 to <15 | 613 | 6 | 5.74 (2.07 to 15.89) | <.001 |
| 15 to <25 | 1052 | 10 | 4.46 (1.81 to 10.97) | .001 |
| 25+ | 689 | 5 | 2.69 (0.88 to 8.24) | .08 |
| Never smokers (referent) | 10 463 | 12 | 1.00 | − |
*
This analysis is limited to never smokers and former smokers with at least 21.3 cumulative pack-years. CI = confidence interval; YSQ = years since quitting.
†
Hazard ratios are adjusted for age, sex, education, examination decade, and alcohol consumption. All variables are time-updated.
‡
P values were derived from a two-sided χ2 test.