Table 1

Model goodness of fit and association of lung cancer risk with indicators of cumulative exposure to asbestos fibres, estimated by Poisson regression with adjustment for age, sex, race, calendar time and birth cohort

Exposure indicator (f-y/ml)	β	SE (β)	∆	LR	p	AIC
PCM fibres	0.00101	0.00028	0.0333	9.6	0.002	2343.1
Total TEM fibres	0.00005	0.00002	0.0310	7.6	0.006	2345.1
TEM fibres ≥5 μm	0.00039	0.00012	0.0312	8.5	0.004	2344.2
TEM fibres <5 μm	0.00006	0.00002	0.0297	7.4	0.010	2345.3

AIC, Akaike Information Criterion (smaller values indicate better fit); β and SE, regression coefficient and associated standard error; ∆, change in lung cancer risk for increment in exposure equal to 1 IQR; LR, likelihood ratio test statistic (equivalent to χ² with 1 degree of freedom) and associated p value; PCM, phase-contrast light miscroscopy; TEM, transmission electron microscopy.