Table 1

 Group comparison of demographic parameters, pre-employment spirometry, and bronchodilator tests

GroupingMiners (n = 317)Referents (n = 132)p Value
Value represents mean (standard deviation).
†Percent change in post-, and prebronchodilator FEV1; one miner missed bronchodilator test.
Age22.3 (2.6)17.5 (0.8)0.0001
Height (cm)170 (4.7)170 (5.5)0.5124
Weight (kg)63 (5.6)58 (7.5)0.0001
Smoking (pack years)0.7 (1.7)0.0 (0.0)0.0001
FEV1 (l)4.47 (0.50)4.28 (0.48)0.0002
FVC (l)5.29 (0.58)4.82 (0.60)0.0001
FEV1/FVC (%)84.8 (7.0)89.0 (5.9)0.0001
PP FEV1 (%)103.5 (10.1)105.4 (9.8)0.0668
Δ FEV1-BD (%)†3.1 (5.5)2.8 (3.7)0.5131