Quintiles of measures of vibration exposure | ||||||||
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Models | 1st | 2nd | 3rd | 4th | 5th | LR test (χ^{2}, 4 df†) | H-L test (χ^{2}, 8 df†) | |

In the logistic regression models, the measures of vibration exposure were included as quintile based design variables, assuming the lowest quintile as the reference category. The likelihood ratio (LR) test for the measures of vibration exposure, and the Hosmer-Lemeshow (H-L) test for the goodness of fit of the logistic models are given. | ||||||||

*p<0.001, †df = degrees of freedom. | ||||||||

Model 1: | ||||||||

a_{h,w(eq,T)}(ms^{−2}) | midpoint | 2.6 | 5.1 | 7.1 | 17.0 | 20.7 | ||

OR (95% CI) | 1.0 (–) | 4.7 (2.9 to 7.6) | 3.6 (2.3 to 5.7) | 3.9 (2.5 to 6.1) | 3.5 (2.2 to 5.8) | 60.2* | 6.55 | |

Total operating time (h) | midpoint | 900 | 3100 | 6800 | 15000 | 37500 | (p=0.59) | |

OR (95% CI) | 1.0 (–) | 2.2 (1.3 to 3.8) | 2.2 (1.3 to 3.7) | 5.5 (3.3 to 9.1) | 9.7 (5.6 to 16.7) | 111.2* | ||

Model 2: | ||||||||

a_{h,uw(eq,T)}(ms^{−2}) | midpoint | 34.3 | 49.2 | 62.7 | 97.7 | 120 | ||

OR (95% CI) | 1.0 (–) | 4.9 (3.0 to 7.9) | 3.7 (2.3 to 5.8) | 4.3 (2.8 to 6.8) | 3.3 (2.0 to 5.3) | 65.2* | 4.51 | |

Total operating time (h) | midpoint | 900 | 3100 | 6800 | 15000 | 37500 | (p=0.81) | |

OR (95% CI) | 1.0 (–) | 2.2 (1.3 to 3.6) | 2.2 (1.3 to 3.7) | 5.5 (3.3 to 9.2) | 9.5 (5.5 to 16.3) | 106.2* | ||

Model 3: | ||||||||

a_{h,w(eq,T)}(ms^{−2}) | midpoint | 2.6 | 5.1 | 7.1 | 17.0 | 20.7 | ||

OR (95% CI) | 1.0 (–) | 3.7 (2.4 to 5.9) | 3.8 (2.4 to 5.9) | 4.0 (2.5 to 6.2) | 2.5 (1.6 to 4.0) | 56.6* | 16.8 | |

Years of exposure (y) | midpoint | 3 | 7 | 12 | 21 | 33 | (p=0.03) | |

OR (95% CI) | 1.0 (–) | 2.7 (1.6 to 4.6) | 3.2 (1.9 to 5.4) | 4.6 (2.7 to 7.8) | 7.1 (4.0 to 12.6) | 53.1* | ||

Model 4: | ||||||||

a_{h,uw(eq,T)}(ms^{−2}) | midpoint | 34.3 | 49.2 | 62.7 | 97.7 | 120 | ||

OR (95% CI) | 1.0 (–) | 4.0 (2.5 to 6.4) | 3.9 (2.5 to 6.1) | 4.5 (2.9 to 7.0) | 2.3 (1.4 to 3.6) | 66.8* | 19.0 | |

Years of exposure (y) | midpoint | 3 | 7 | 12 | 21 | 33 | (p=0.02) | |

OR (95% CI) | 1.0 (–) | 2.7 (1.6 to 4.6) | 3.3 (1.9 to 5.5) | 4.7 (2.7 to 8.1) | 7.3 (4.1 to 13.1) | 53.2* |