Table 2.

Cross-sectional analysis^† of FVC and FEV₁ at first test date for 933 currently employed males compared to the lowest exposed group^‡

Subjects at first test (n=933)	FVC	FEV1
Slope at age 40 (95% CI)§	−35.7*** (−42.7 to −28.6) (ml/year)	−37.1*** (−42.9 to −31.2) (ml/year)
Cumulative fibre (15–60 fibre-months/cc)‡	−50.7 ml	−83.7 ml
Cumulative fibre (>60 fibre-months/cc)‡	−198.2 ml**	−154.8 ml**
Pack-years at first test	−1.2 ml/pack-year	−4.2**ml/pack-year
Current smoker at time of test	−121.2 ml*	−193.3 ml***
Weight	−4.1 ml/kg**	−3.8 ml/kg***
Categorical plant (4 df)	p=0.47	p=0.26

^*p<0.05;

^**p<0.01

^***p<0.001.

^†Regression model included restricted cubic spline function of age, categorical cumulative fibre (fibre-months/cc), continuously modelled pack-years (pack-year), current smoker at time of test (yes/no), continuously modelled body weight (kg), dummy variables describing five plant locations. Spirometer measurements were adjusted for height, race and spirometer. Technician was modelled as a random effect.

^‡Compared to reference group having <15 RCF fibre-months/cc exposure.

^§Mean age at first test was 36.5 years.