Table 2.
β Coefficients and 95% CIs of each variable versus %FEV1 by model and population
| In all the subjects | In smokers | |||
|---|---|---|---|---|
| Model 1# | Model 2## | Model 1# | Model 2## | |
| Per 10 pack-years | -0.021 (-0.036, -0.006)** | -0.021 (-0.036, -0.006)** | -0.020 (-0.042, 0.002) | -0.020 (-0.042, 0.002) |
| Male | 0.017 (-0.054, 0.088) | Not assessed | -0.034 (-0.144, 0.077) | Not assessed |
| White | 0.088 (0.012, 0.163)* | 0.093 (0.020, 0.165)* | 0.050 (-0.086, 0.187) | 0.052 (-0.083, 0.188) |
| Restrictive lung diseases | -0.167 (-0.270, -0.065)** | -0.174 (-0.272, -0.077)** | -0.133 (-0.309, 0.042) | -0.121 (-0.290, 0.049) |
All the results were from the multiple linear regression analysis, in which the dependent variable was %FEV1. Pack-year of smoking was calculated by multiplying the number of packs of cigarette smoked per day and the number of years of smoking. Restrictive lung function was defined as FEV1/FVC ≥ 70% and %FVC < 80%, either before or after salbutamol inhalation.
# In model 1, the association between %FEV1 and pack-years of smoking was adjusted for by gender, race and restrictive lung diseases. R2 = 0.210 in all the subjects and R2 = 0.084 in smokers.
## In model 2, the association between %FEV1 and pack-years of smoking was adjusted for by race and restrictive lung diseases. R2 = 0.209 in all the subjects and R2 = 0.080 in smokers.
* p < 0.05 for β coefficient. **p < 0.01 for β coefficient.