Table III.
Total Lung Diseases in Complete Sample Regression Results
| Estimate | Std. Error | t Value | p Value | Incident Risk Ratio (IRR) |
IRR 95% CI Lower Bound |
IRR 95% CI Upper Bound |
|
|---|---|---|---|---|---|---|---|
| Base Model: Control variables | |||||||
| Miner age | 0.03 | 0.01 | 1.80 | 0.07 | 1.03 | 0.99 | 1.06 |
| Mining tenure | 0.11*** | 0.01 | 9.19 | <0.001 | 1.12 | 1.09 | 1.14 |
| Model 1: Management practices | |||||||
| Miner age | −0.04 | 0.03 | −1.34 | 0.18 | 0.96 | 0.90 | 1.02 |
| Mining tenure | 0.13*** | 0.03 | 3.66 | <0.001 | 1.13 | 1.06 | 1.21 |
| Commodity | 2.77*** | 0.31 | 9.05 | <0.001 | 16.01 | 8.78 | 29.21 |
| Management practices | 0.13* | 0.06 | 2.16 | 0.03 | 1.14 | 1.02 | 1.29 |
| Model 2: Engineering controls | |||||||
| Miner age | −0.04 | 0.04 | −0.96 | 0.34 | 0.97 | 0.90 | 1.04 |
| Mining tenure | 0.13*** | 0.04 | 3.32 | <0.001 | 1.13 | 1.05 | 1.22 |
| Commodity | 2.88*** | 0.32 | 8.92 | <0.001 | 17.80 | 9.45 | 33.50 |
| Engineering controls | 0.20*** | 0.06 | 3.22 | <0.001 | 1.22 | 1.08 | 1.37 |
Note: n = 8,165.
***
p < 0.001;
**
p < 0.01;
*
p < 0.05. For commodity, coal is contrasted with all non-coal commodities with noncoal commodities as the reference group. The interaction terms between workplace practices and conditions from 1996–2005 and mining commodity were not significant.