Table 4 Association between PTB on history or radiograph and different exposure metrics.

Exposure metric	Prevalence odds ratio	95% CI	Prevalence odds ratio, scaled in IQR units	95% CI
Length of service in years	1.042*	1.000 to 1.086	1.31	1.00 to 1.72
	(1.032)†	(0.990 to 1.077)	(1.24)	(0.94 to 1.63)
	(1.026)‡	(0.984 to 1.070)	(1.19)	(0.90 to 1.57)
	[1.033]§	[0.983 to 1.085]	[1.24]	[0.89 to 1.71]
Cumulative respirable dust (mg.years/m3)	1.107	1.036 to 1.183	1.45	1.14 to 1.85
	(1.093)	(1.021 to 1.170)	(1.38)	(1.08 to 1.77)
	(1.080)	(1.008 to 1.156)	(1.32)	(1.03 to 1.70)
	[1.097]	[1.010 to 1.191]	[1.40]	[1.04 to 1.89]
Average intensity respirable dust (μg/m3)¶	1.003	1.001 to 1.005	1.48	1.13 to 1.95
	(1.003)	(1.001 to 1.005)	(1.45)	(1.10 to 1.91)
	(1.002)	(1.000 to 1.004)	(1.41)	(1.06 to 1.86)
	[1.003]	[1.000 to 1.005]	[1.51]	[1.07 to 2.12]
Cumulative respirable quartz (mg.years/m3)	1.950	1.257 to 3.024	1.47	1.14 to 1.89
	(1.811)	(1.158 to 2.831)	(1.41)	(1.09 to 1.82)
	(1.678)	(1.070 to 2.634)	(1.35)	(1.04 to 1.75)
	[1.863]	[1.080 to 3.215]	[1.43]	[1.05 to 1.99]
Average intensity respirable quartz (μg/m3)¶	1.017	1.005 to 1.029	1.44	1.11 to 1.87
	(1.016)	(1.004 to 1.028)	(1.42)	(1.09 to 1.84)
	(1.015)	(1.003 to 1.028)	(1.39)	(1.07 to 1.81)
	[1.018]	[1.003 to 1.033]	[1.47]	[1.07 to 2.03]

*Adjusted for age and smoking, n = 520.

†(Adjusted for age, smoking, and silicosis >1/0 as classified by Reader 1, n = 520).

‡(Adjusted for age, smoking, and silicosis >1/0 as classified by Reader 2, n = 520).

§[In non‐silicotics, adjusted for age and smoking, n = 373].

¶Units for average intensities of exposure are in micrograms to display more easily interpretable prevalence odds ratios.