FEV1, mL (95% CI) | ||||
---|---|---|---|---|
All | Non-smokers | |||
Cessation-years | 14.2*** | (12.0 to 16.5) | 9.4*** | (7.1 to 11.7) |
Cessation-years2 | 0.3*** | (0.1 to 0.4) | 0.3*** | (0.2 to 0.5) |
Cotton×cessation-years | −2.7* | (−5.0 to −0.5) | −1.7† | (−4.2 to 0.7) |
Current smoker×cessation-years | 1.1 | (−2.6 to 4.9) | – | – |
Former smoker×cessation-years | 0.4 | (−4.4 to 5.2) | – | – |
Male×cessation-years | −5.7** | (−9.1 to −2.3) | −4.5** | (−7.8 to −1.3) |
Observations | 4702 | 3068 |
Model adjusted for age, height, gender, exposure (cotton vs silk), smoking (never, current, former), cumulative pack-years and interaction terms between cessation-years and occupational exposure, cessation-years and smoking and cessation-years and gender. Loss to follow-up accounted for by using inverse probability of censoring weights. Note: as the modelled outcome was FEV1 and not change in FEV1, the interaction terms with cessation-years represent the associations between occupational exposure, smoking, gender and change in FEV1 after leaving work.
Quadratic interaction terms were significant only for the male×cessation-years2 term, with β=0.5 (0.2, 0.8), p=0.0009 for all workers and β=0.4 (0.1, 0.7), p=0.02 for the analysis restricted to non-smokers.
*p<0.05; **p<0.01; ***p<0.001.
†Cotton×cessation-years interaction p=0.08 in analysis restricted to non-smokers.
FEV1, forced expiratory volume in 1 s.