Table 3. HR and 95% CI for duration worked underground—mortality and incidence.
| |
Never underground (reference) |
<20 years undergrounda |
20+ years undergrounda |
Ptrendb |
||||
|---|---|---|---|---|---|---|---|---|
| n | n | HRc | 95% CI | n | HRc | 95% CI | ||
|
Mortality | ||||||||
| Any cause | 345 | 724 | 1.21 | 1.06–1.37 | 853 | 1.25 | 1.10–1.42 | 0.003 |
| Any cancer | 76 | 178 | 1.29 | 0.98–1.69 | 201 | 1.31 | 1.00–1.71 | 0.134 |
| Lung cancer | 20 | 74 | 1.93 | 1.17–3.16 | 88 | 1.93 | 1.19–3.15 | 0.115 |
| Prostate cancer |
12 |
12 |
0.63 |
0.28–1.40 |
13 |
0.64 |
0.30–1.40 |
0.694 |
|
Incidence | ||||||||
| Any cancer | 84 | 195 | 1.04 | 0.80–1.34 | 198 | 1.15 | 0.89–1.49 | 0.344 |
| Lung cancer | 15 | 39 | 1.09 | 0.60–2.00 | 56 | 1.57 | 0.88–2.77 | 0.096 |
| Prostate cancer | 25 | 52 | 1.08 | 0.67–1.74 | 45 | 0.99 | 0.61–1.63 | 0.987 |
Abbreviations: CI=confidence intervals; HR=hazard ratio.
a
Median duration of underground work was 240 months (20 years) among ever-underground miners.
b
P-value for trend (continuous duration: months worked underground).
c
All HRs are adjusted for year of birth, HRs for lung and any cancer are additionally adjusted for smoking (duration in years).