Table 1

Exposure-response estimates of mortality for lung cancer and silica by Poisson regression comparing several specifications of exposure with lag of 10 years (77 lung cancer deaths)

Model^1-150	β₁Estimate	Change (−2ln likelihood)	p Value^1-151	RR at 1.0 mg/m³.y^1-152	RR at mean^1-153	RR at maximum^1-153
Log linear (1a):
Internal adjustment	0.0508	4.946	0.026	1.052	1.221	4.728
External adjustment	0.0402	5.530	0.019	1.041	1.172	3.422
Log square root (1b):
Internal adjustment	0.3182	6.973	0.008	1.375	1.880	5.809
External adjustment	0.3013	8.996	0.003	1.352	1.819	5.290
Log quadratic (1c):
Internal adjustment:	β₁	0.1377	—	—	—	—	—
Internal adjustment:	β₂	−0.00327	8.309	0.0157	1.144	1.634	3.169
External adjustment:	β₁	0.1168	—	—	—	—	—
External adjustment:	β₂	−0.00216	10.29	0.0058	1.121	1.531	4.721
Power (1d):
Internal adjustment	0.4268	6.957	0.008	1.344	1.976	4.364
External adjustment	0.4301	9.193	0.002	1.347	1.987	4.414
Linear relative rate (1e):
Internal adjustment	0.1629	7.589	0.006	1.163	1.641	5.980
External adjustment	0.1441	9.127	0.003	1.144	1.567	5.405
Additive excess rate (2):
External adjustment	0.000088	2.943	0.09	—^1-154	—^1-154	—^1-154

↵1-150 Internal adjustment models: stratifying on time since first observed (3 levels), calendar time (9 levels), age (13 levels), and ethnicity (Hispanics v other). External adjustment models: stratifying on ethnicity (Hispanicsv other) and time since first observed (3 levels) with external adjustment for age and calendar time using person-y (US rate). Cumulative exposure was classified in 50 levels in addition to the unexposed level.
↵1-151 Likelihood ratio test for an exposure effect. (The log quadratic model test is based on two degrees of freedom.)
↵1-152 Estimate for cumulative exposure of 1.0 mg/m³.y.
↵1-153 Evaluated at mean and maximum estimated cumulative exposures of deaths from lung cancer.
↵1-154 Not a relative rate model.