Table 3 PTB status across the variables of interest

Age at certification, years, Mean, (SD) ^a*

34 (6.0)

31.0 (6.2)

 Non-smokers, n, (%)

22 (64.7)

273 (84.5)

 Current smokers, n, (%)^**

12 (35.3)

39 (12.1)

Length of service, Mean, (SD) ^a*

6.1 (2.0)

5.1 (2.5)

 Male, n, (%)

34 (9.5)

323 (90.5)

Cumulative respirable silica Dust Exposure, Mean, (SD) ^a**

2.2 (1.0)

1.5 (0.9)

 Low, n, (%)

3 (8.8)

116 (35.9)

 Medium, n, (%)^*

10 (29.4)

105 (32.5)

 High, n, (%)^**

21 (61.8)

102 (31.6)