Table 3.
Incidence and hazard ratio of incident lung cancer in participants with bronchiectasis versus those without bronchiectasis with stratified analysis by smoking status and chronic obstructive pulmonary disease
| Number of Participants | Number of Lung Cancer | IR (/1,000 PY) | IRR* (95% Confidence Interval) | Hazard Ratio (95% Confidence Interval) |
||||
|---|---|---|---|---|---|---|---|---|
| Unadjusted | Model 1 | Model 2 | Model 3 | |||||
| Never-smoker† | ||||||||
| No bronchiectasis | 2,279,598 | 9,907 | 0.527 | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) |
| Bronchiectasis | 44,007 | 493 | 1.395 | 1.30 (1.18–1.43) | 2.65 (2.42–2.90) | 1.44 (1.31–1.57) | 1.30 (1.18–1.43) | 1.28 (1.17–1.41) |
| Ever-smoker† | ||||||||
| No bronchiectasis | 523,695 | 4,172 | 0.973 | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) |
| Bronchiectasis | 10,291 | 259 | 3.217 | 1.29 (1.13–1.47) | 3.31(2.92–3.75) | 1.46 (1.28–1.66) | 1.29 (1.13–1.47) | 1.26 (1.10–1.44) |
| Ever smokers†, pack-years | ||||||||
| <10 pack-years | ||||||||
| No bronchiectasis | 582,471 | 1,445 | 0.300 | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) |
| Bronchiectasis | 5,440 | 62 | 1.412 | 1.25 (0.96–1.63) | 4.70 (3.64–6.06) | 1.45 (1.12–1.88) | 1.25 (0.96–1.64) | 1.23 (0.94–1.61) |
| 10–19 pack-years | ||||||||
| No bronchiectasis | 440,473 | 2,226 | 0.616 | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) |
| Bronchiectasis | 5,260 | 89 | 2.122 | 1.21 (0.97–1.50) | 3.45 (2.79–4.26) | 1.33 (1.07–1.64) | 1.21 (0.97–1.50) | 1.21 (0.97–1.51) |
| ⩾20 pack-years | ||||||||
| No bronchiectasis | 490,575 | 9,537 | 2.416 | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) |
| Bronchiectasis | 10,598 | 448 | 5.532 | 1.17 (1.06–1.29) | 2.30 (2.09–2.53) | 1.28 (1.16–1.40) | 1.18 (1.07–1.30) | 1.14 (1.03–1.26) |
| P for interaction | 0.76 | <0.001 | 0.25 | 0.25 | 0.92 | |||
| Without COPD | ||||||||
| No bronchiectasis | 3,622,938 | 19,290 | 0.647 | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) |
| Bronchiectasis | 43,822 | 489 | 1.372 | 1.19 (1.09–1.30) | 2.12 (1.94–2.32) | 1.25 (1.14–1.37) | 1.19 (1.09–1.30) | 1.19 (1.09–1.31) |
| With COPD | ||||||||
| No bronchiectasis | 170,179 | 3,825 | 2.865 | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) |
| Bronchiectasis | 21,483 | 603 | 3.680 | 1.08 (0.99–1.18) | 1.29 (1.18–1.40) | 1.17 (1.07–1.27) | 1.08 (0.99–1.18) | 1.06 (0.97–1.16) |
| P for interaction | 0.20 | <0.001 | 0.30 | 0.15 | 0.07 | |||
Definition of abbreviations: COPD = chronic obstructive pulmonary disease; IR = incidence rate; IRR = incidence rate ratio; PY = person-years.
Model 1 was adjusted for age, sex, body mass index, smoking history (never-smoker, ever-smoker with <10 pack-years, ever-smoker with 10–19 pack-years, and ever-smoker with ⩾20 pack-years), alcohol consumption (none, mild, or heavy), income level (low or high), physical activity (regular or nonregular), and Charlson Comorbidity Index (0, 1, or ⩾2); model 2 was further adjusted for the number of chest computed tomography scans performed; and model 3 additionally considered mortality as a competing risk.
Variables in Model 3 were adjusted.
The abovementioned variables, except smoking status, were used in each model.