Variable a | FEV1 (ml/s) | FVC (ml) | FEV1/FVC (%) |
|---|
Male (n = 5864) | Female (n = 1260) | Male (n = 5864) | Female (n = 1260) | Male (n = 5864) | Female (n = 1260) |
|---|
β | SE | P | β | SE | P | β | SE | P | β | SE | P | β | SE | P | β | SE | P |
|---|
Change of WBC *TIC | − 0.90 | 0.2 |  < 0.0001 | − 1.18 | 0.3 |  < 0.0001 | − 0.80 | 0.2 |  < 0.0001 | − 1.34 | 0.4 |  < 0.0001 | − 0.004 | 0.002 | 0.050 | 0.001 | 0.005 | 0.840 |
Change of NEU * TIC | − 0.71 | 0.2 |  < 0.0001 | − 0.96 | 0.3 | 0.001 | − 0.75 | 0.2 |  < 0.0001 | − 0.99 | 0.3 | 0.004 | − 0.001 | 0.002 | 0.455 | − 0.003 | 0.005 | 0.611 |
Change of LYM *TIC | − 0.43 | 0.2 | 0.006 | − 0.24 | 0.3 | 0.448 | − 0.05 | 0.2 | 0.790 | − 0.49 | 0.4 | 0.177 | − 0.009 | 0.002 |  < 0.0001 | 0.006 | 0.005 | 0.269 |
Change of MID * TIC | − 1.03 | 0.1 |  < 0.0001 | − 1.37 | 0.3 |  < 0.0001 | − 1.14 | 0.1 |  < 0.0001 | − 1.62 | 0.3 |  < 0.0001 | − 0.0003 | 0.002 | 0.834 | 0.002 | 0.004 | 0.658 |
- WBC  white blood count, NEU  neutrophilicgranulocyte, LYM  lymphocyte, MID  mid-range absolute count including monocytes, eosinophils and basophils, SE  standard error of mean, TIC  time in cohort
- aDelta change was calculated as values of WBC and its differential for each non-baseline visit minus baseline value for each individual and was included in the model for assessing its association with lung function decline. The model used longitudinal lung function measurements as the outcome and included age, smoking status (male only), packyears (male only), height, BMI, TIC, TWEI, years of dust exposure, baseline spirometry, baseline WBC and its differential, delta change of WBC and its differential, and interaction terms of TIC with TWEI, baseline spirometry, years of dust exposure, baseline WBC and its differential, and delta change of WBC and its differential. A negative β of the interaction term between TIC and delta change of WBC indicated that an increase in WBC post-baseline was associated with a more rapid decline of lung function. β and standard error of the mean was calculated using the interquartile range as the unit of change. Inter-quartile ranges for delta changes were calculated based on the distribution of annual changes of WBC (i.e., last WBC – baseline WBC / TIC) and its differential in cohort members with positive delta change values (n = 2211, 2360, 2235, and 1355 for WBC, NEU, LYM, and MID, respectively). WBC: 0.187*109/L; NEU: 0.150*109/L; LYM: 0.060*109/L; MID: 0.014*109/L. The inter-quartile range values were not sex-specific because we want to quantitatively compare the magnitude of associations between sexes
