Table 6

 Model for asbestosis mortality as an underlying or contributing cause of death among workers in the South Carolina asbestos textile workers cohort*

Term in modelEstimateStandard errorLikelihood ratio test†
*Power model for asbestosis mortality rate is given by λ = λ0 × (E + α)β where λ0 = exp[β0 + β1(sex = female) + β2(race = non-white) + β3(age = 50–59 years) + β4(age = 60–74 years) + β5(age = 75+ years) + β6(birth cohort = prior to 1920)], E is cumulative chrysotile exposure (in fibre-years/ml), α = 0.9 (estimated iteratively), and β =  (β7 + β8(age = 50–59 years) + β9(age = 60–74 years) + β10(age = 75+ years)).
†Likelihood ratio χ2 statistic, degrees of freedom, p value.
Interceptβ0−14.41.94
SexMaleRef10.5, 1, 0.0012
Femaleβ1−0.9380.299
RaceWhiteRef11.9, 1, 0.0006
Non-whiteβ2−1.200.390
Age<50 yearsRef20.4, 3, 0.0001
50–59 yearsβ31.062.59
60–74 yearsβ43.322.14
75+ yearsβ56.622.07
Birth cohort1920+Ref5.54, 1, 0.019
<1920β60.8110.373
ExposureFibre-years/ml; no lagα0.9
β71.520.41795.5, 1, <0.0001
Exposure×age<50 yearsRef9.30, 3, 0.026
50–59 yearsβ8−0.01750.540
60–74 yearsβ9−0.3140.456
75+ yearsβ10−0.8970.451