Table 4

Regression coefficients for adjusted lung function indices for subjects with age ≥18 years and history in coke ovens ≥1 year at the dates of last sets of lung function tests

FEV1 (l)FVC (l)FEV1/FVC (%)FEF25–75% (l/s)
Coefficientp valueCoefficientp valueCoefficientp valueCoefficientp value
*Limits of 95% CI for the parameter.
†FEF25–75% was measured after January 1983, therefore the number of observations is smaller than that for FEV1, FVC and FEV1/FVC.
Intercept3.70 (3.54 to 3.85)*0.00014.54 (4.37 to 4.70)0.000180.9 (78.6 to 83.1)0.00013.99 (3.46 to 4.52)0.0001
Ex-smokers0.166 (0 to 0.331)0.05170.139 (−0.0376 to 0.315)0.1262.62 (0.225 to 5.02)0.03340.272 (−0.166 to 0.710)0.230
Duration of smoking for ex-smokers (years)−0.0128 (−0.0200 to −0.0055)0.0006−0.00805 (−0.0157 to −0.00035)0.0420−0.253 (−0.358 to −0.148)0.0001−0.0358 (−0.0548 to −0.0167)0.0003
Current smokers−0.116 (−0.223 to −0.010)0.0341−0.0390 (−0.152 to 0.074)0.503−1.85 (−3.40 to −0.31)0.0195−0.304 (−0.643 to 0.035)0.0822
Pack-years for current smokers−0.000181 (−0.00285 to 0.00249)0.895−0.000550 (−0.00339 to 0.00229)0.706−0.0407 (−0.0793 to −0.00208)0.0404−0.0198 (−0.0310 to −0.0087)0.0006
Operation0.0120 (−0.143 to 0.167)0.880−0.0707 (−0.235 to 0.094)0.4031.74 (−0.49 to 3.98)0.1290.0327 (−0.504 to 0.570)0.906
Maintenance−0.0164 (−0.154 to 0.121)0.816−0.0151 (−0.161 to 0.131)0.8410.207 (−1.78 to 2.19)0.8390.0869 (−0.399 to 0.573)0.729
Electricity−0.0359 (−0.187 to 0.115)0.644−0.0495 (−0.210 to 0.111)0.548−0.226 (−2.41 to 1.96)0.840−0.0429 (−0.575 to 0.489)0.876
Work duration in “operation” (years)−0.00945 (−0.0162 to −0.0027)0.0062−0.0116 (−0.0187 to −0.0044)0.0016−0.0856 (−0.183 to 0.012)0.0866−0.00239 (−0.0234 to 0.0186)0.825
Work duration other than in “operation” (years)−0.00206 (−0.00853 to 0.00441)0.536−0.00748 (−0.0144 to −0.0006)0.03440.0695 (−0.0241 to 0.163)0.1490.00705 (−0.0133 to 0.0274)0.502
R square0.03720.03580.05080.0811
No. of observations†834833833500