Table 5

 Hazard ratio estimates of nasopharyngeal carcinoma in relation to cumulative quantitative cotton dust and endotoxin exposures

ExposureCasesNon-casesHR†95% CIp for trend
†Adjusted for age at baseline only.
Cotton dust (mg/m3 × years)
    None1610161.0Reference
    >0 to 55.9125431.2(0.6 to 2.5)
    >55.9 to 97.0125431.4(0.6 to 2.9)
    >97.0 to 143.465421.0(0.4 to 2.5)
    >143.4215433.6(1.8 to 7.2)<0.001
Endotoxin (EU/m3 × years)
    None129161.0Reference
    >0 to 1517.4175312.1(1.0 to 4.5)
    >1517.4 to 2430.095301.3(0.6 to 3.2)
    >2430.0 to 3530.675311.2(0.5 to 3.2)
    >3530.6145302.5(1.1 to 5.4)0.09