Occupational asbestos exposure, smoking and IPF (n=960)
| Exposure* | Adjusted OR† (95% CI; p value) |
| Ever asbestos exposed | 1.1 (0.8 to 1.4; 0.60) |
| High-risk non-construction | 0.9 (0.6 to 1.6; 0.8) |
| High-risk construction | 1.1 (0.7 to 1.7; 0.73) |
| Medium risk industrial | 0.9 (0.6 to 1.5; 0.78) |
| Low risk industrial | 0.9 (0.6 to 1.4; 0.57) |
| Office | 1 |
| Ever smoked | 1.4 (1 to 1.9; 0.04) |
| Interaction model (asbestos∗smoking) | |
| Ever asbestos exposed | 0.7 (0.4 to 1.2; 0.20) |
| Ever smoked | 1.0 (0.6 to 1.6; 0.83) |
| Ever asbestos exposed and ever smoked interaction | 1.9 (1 to 3.6; 0.04) |
*Categories of occupational asbestos exposure risk were defined on the basis of occupational proportional mortality ratios for mesothelioma16 and ever asbestos exposed was defined as ever having had a high or medium asbestos exposure risk job.
†Adjusted for age, centre and smoking; smoking was not adjusted for when it was the exposure under consideration.
IPF, idiopathic pulmonary fibrosis.