Model goodness of fit and association of lung cancer risk with cumulative exposure to asbestos fibres by size category, estimated by Poisson regression with adjustment for age, sex, race, calendar time and birth cohort
| Length (μm) | Diameter (μm) | ||||
| <0.25 | 0.25–1.0 | 1.0–3.0 | >3.0 | All | |
| ≤1.5 | |||||
| AIC | 2343.9 | 2350.2 | – | – | 2344.1 |
| ∆ | 0.0328 | 0.0149 | 0.0323 | ||
| LR | 8.8 | 2.5 | 8.6 | ||
| 1.5–5 | |||||
| AIC | 2347.5 | 2349.1 | 2349.7 | – | 2347.8 |
| ∆ | 0.0229 | 0.0127 | 0.0133 | 0.0156 | |
| LR | 5.2 | 3.6 | 3.0 | 5.0 | |
| 5–10 | |||||
| AIC | 2346.4 | 2345.3 | 2347.4 | 2350.2 | 2345.7 |
| ∆ | 0.0210 | 0.0288 | 0.0157 | 0.0007 | 0.0250 |
| LR | 6.3 | 7.4 | 5.3 | 2.5 | 7.0 |
| 10–20 | |||||
| AIC | 2345.4 | 2343.9 | 2346.3 | 2349.3 | 2344.3 |
| ∆ | 0.0290 | 0.0327 | 0.0208 | 0.0082 | 0.0327 |
| LR | 7.3 | 8.8 | 6.4 | 3.4 | 8.4 |
| 20–40 | |||||
| AIC | 2342.6 | 2340.7 | 2344.1 | 2338.2 | 2340.0 |
| ∆ | 0.0337 | 0.0326 | 0.0203 | 0.0265 | 0.0371 |
| LR | 10.1 | 12.1 | 8.6 | 14.5 | 12.7 |
| >40 | |||||
| AIC | 2344.1 | 2340.9 | 2346.9 | 2345.1 | 2341.8 |
| ∆ | 0.0367 | 0.0367 | 0.0225 | 0.0144 | 0.0367 |
| LR | 8.6 | 11.8 | 5.9 | 7.6 | 10.9 |
| All | |||||
| AIC | 2344.9 | 2347.5 | 2346.4 | 2342.6 | 2345.1 |
| ∆ | 0.0310 | 0.0202 | 0.0242 | 0.0256 | 0.0310 |
| LR | 7.8 | 5.2 | 6.3 | 10.1 | 7.6 |
Structures ≤1.5 μm long and >1 μm wide and 1.5–5 μm wide and >3 μm wide do not meet the definition of a fibre and were not counted.
AIC, Akaike Information Criterion (smaller values indicate better fit); ∆, change in lung cancer risk for increment in exposure equal to 1 IQR; LR, likelihood ratio (equivalent to χ2 with 1 degree of freedom).