Table 4.

Estimated Association Between Radon Exposure and Lung Cancer Mortality Obtained From Fitting a Log-Linear Regression Model to Data on Colorado Plateau Uranium Miners, 1950–1990^a

Model	$\stackrel{\mathbf{ˆ}}{\mathbf{\beta }}$	95% CI Estimate
		Robust 95% CIb	Robust 95% CIc	Bootstrap 95% CId	Bootstrap 95% CIe
$\mathrm{\phi }\left(Z;\mathrm{\beta }\right)=\exp \left(\mathrm{\beta }Z\right)$	0.04	0.03, 0.05	0.03, 0.05	0.03, 0.05	0.03, 0.05

Abbreviation: CI, confidence interval.

^a We used data from a study of lung cancer among 2,704 men employed in underground uranium mining operations on the Colorado Plateau between January 1, 1950, and December 31, 1960 (27, 28).

^b Robust 95% CI obtained using SAS PHREG with the “covsandwich” option as in the article by Langholz and Jiao (11).

^c Robust 95% CI obtained using the approach described in this paper.

^d Bootstrapped 95% CI based on the bootstrap variance and Wald-type interval.

^e Bootstrapped 95% CI based on percentiles of the bootstrap estimates.