Table 5 Hazard ratio estimates of nasopharyngeal carcinoma in relation to cumulative quantitative cotton dust and endotoxin exposures.
| Exposure | Cases | Non‐cases | HR† | 95% CI | p for trend |
|---|---|---|---|---|---|
| Cotton dust (mg/m3 × years) | |||||
| None | 16 | 1016 | 1.0 | Reference | |
| >0 to 55.9 | 12 | 543 | 1.2 | (0.6 to 2.5) | |
| >55.9 to 97.0 | 12 | 543 | 1.4 | (0.6 to 2.9) | |
| >97.0 to 143.4 | 6 | 542 | 1.0 | (0.4 to 2.5) | |
| >143.4 | 21 | 543 | 3.6 | (1.8 to 7.2) | <0.001 |
| Endotoxin (EU/m3 × years) | |||||
| None | 12 | 916 | 1.0 | Reference | |
| >0 to 1517.4 | 17 | 531 | 2.1 | (1.0 to 4.5) | |
| >1517.4 to 2430.0 | 9 | 530 | 1.3 | (0.6 to 3.2) | |
| >2430.0 to 3530.6 | 7 | 531 | 1.2 | (0.5 to 3.2) | |
| >3530.6 | 14 | 530 | 2.5 | (1.1 to 5.4) | 0.09 |
†Adjusted for age at baseline only.