Three tin mines in Dachang | Limu tin mine | Total | |||||||
---|---|---|---|---|---|---|---|---|---|
Silicosis | Cases | Controls | OR (95% CI) | Cases | Controls | OR (95% CI) | Cases | Controls | OR (95% CI) |
*Adjusted for cigarette smoking; †two sided p value. | |||||||||
No | 52 | 353 | 1.0 (—) | 20 | 89 | 1.0 (—) | 72 | 442 | 1.0 (—) |
Stage I | 31 | 77 | 2.3 (1.3 to 3.9) | 2 | 24 | 0.4 (0.1 to 1.6) | 33 | 101 | 1.9 (1.2 to 3.0) |
Stage II | 15 | 45 | 2.2 (1.1 to 4.3) | 6 | 19 | 1.4 (0.5 to 3.9) | 21 | 64 | 2.0 (1.1 to 3.4) |
Stage III | 3 | 14 | 1.4 (0.4 to 5.0) | 1 | 6 | 0.7 (0.1 to 5.7) | 4 | 20 | 1.2 (0.4 to 3.5) |
p Value for trend† | χ2=18.07 p=0.001 | χ2=2.6 p=0.461 | χ2=12.25 p=0.007 |