Table 3

 Results for regression analyses for annual rates of change (time slopes) for FVC, FEV1, FEV1/FVC, and FEF25–75% for all subjects in the coke oven lung function surveillance system

FVC (ml/year)FEV1 (ml/year)FEV1/FVC (%/year)FEF25–75% (ml/s⋅year)
Coefficient95% CIp valueCoefficient95% CIp valueCoefficient95% CIp valueCoefficient95% CIp value
FEF25–75% was measured after January 1983, so the observation number is smaller than that for FVC, FEV1, and FEV1/FVC.
Intercept29.74.26 to 55.20.022243.021.3 to 64.80.00013.102.47 to 3.730.000182.018.7 to 1450.0112
% of predicted value at first test time−0.383−0.655 to −0.1100.0061−0.496−0.722 to −0.2700.0001−0.0306−0.36 to −0.240.0001−0.610−1.18 to −0.0460.0342
Duration of smoking for ex-smokers (y)−0.317−0.676 to 0.0420.0841−0.528−0.878 to −0.1780.0032−0.0111−0.017 to −0.0050.0004−0.597−2.25 to 1.060.478
Pack-years for current smokers−0.496−0.778 to −0.2140.0006−0.608−0.884 to −0.3330.0001−0.00897−0.013 to −0.0040.0003−1.10−2.36 to 0.1590.0865
Work duration in “operation” (y)−0.682−1.25 to −0.1100.0195−0.484−1.04 to 0.0720.08820.0002−0.009 to 0.0090.968−0.0106−2.71 to 2.500.936
Work duration other than in “operation” (y)−0.591−1.12 to −0.0640.0278−0.428−0.940 to 0.0820.1000.0025−0.006 to 0.0110.5820.0176−2.37 to 2.410.989
Number of observations580580580419