Table 3.

Fully adjusted shared frailty model showing the effect union status and other covariates on risk of reportable injuries^{a b}

	Reportable injuries
	HR	95% CI	p value
Union			<0.001
No	1
Yes	1.51	(1.125–1.840)
Age (1-year increase)	0.994	(0.990–0.998)	0.001
Tenure			<0.001
>1 year	1
<1 year	1.24	(1.137–1.355)
Sex			<0.001
Male	1
Female	1.36	(1.230–1.504)
Race			0.137
White	1
Asian	0.85	(0.517–1.392)
Black	1.01	(0.901–1.123)
Other	1.16	(1.017–1.320)

^aStandard job category was included as a fixed effect (result not shown).

^bPlant was included as a random effect to account for shared frailty among workers within each plant.