Table 3. Exponential and linear models in Cox regression with unlagged cumulative Cr(VI) exposure.
| Variables in model | Exponential model | Linear model | ||||||
|---|---|---|---|---|---|---|---|---|
| Deviance | β (mg/m3-years)−1 |
P-valuea | Deviance | β (mg/m3-years)−1 |
P-valuea | |||
| MLE | 95% CI | MLE | 95% CI | |||||
| Cr(VI) | 1248.10 | 0.22 | (0.16, 0.28) | <0.0001 | 1252.26 | 0.65 | (0.28, 1.37) | <0.0001 |
| Cr(VI), smoking | 1234.95 | 0.19 | (0.12, 0.25) | 0.001 | 1236.45 | 0.58 | (0.22, 1.32) | <0.0001 |
| Cr(VI), smoking, age at hire | 1223.14 | 0.17 | (0.10, 0.24) | 0.0006 | 1225.75 | 0.40 | (0.12, 0.97) | 0.001 |
| Cr(VI), smoking, age at hire, years of exposure (continuous variable) | 1222.48 | 0.15 | (0.064, 0.23) | 0.42 | 1225.34 | 0.29 | (0.042, 1.03) | 0.52 |
| Cr(VI), smoking, age at hire, years of exposure (1–4, 4.1–7.9, ⩾8) | 1222.83 | 0.16 | (0.085, 0.23) | 0.85 | 1225.60 | 0.37 | (0.093, 1.11) | 0.93 |
| Cr(VI), smoking, age at hire, years of exposure (<3.9, 4.0–20.7, ⩾20.8) | 1223.00 | 0.18 | (0.092, 0.25) | 0.93 | 1225.27 | 0.51 | (0.118, 1.63) | 0.79 |
Abbreviations: Cr(VI), cumulative exposure, mg/m3-years; MLE, maximum likelihood estimate.
a
P-values are for the bolded variables that are italicized.