Table 4:

Marginal Cox regression models predicting isolated-asthma, isolated-COPD, and asthma/COPD overlap in the subpopulation with serum drawn between 9/11/2001 and 3/10/2002^ab

Variables	Asthma/COPD Overlap vs. Neither			Isolated-Asthma vs. Neither			Isolated-COPD vs. Neither
	HR	95% CI	p	HR	95% CI	p	HR	95% CI	p
IgEc	2.31	1.14–4.67	0.02d	1.21	0.92–1.58	0.16	1.14	0.81–1.62	0.45
IFN-γc	0.42	0.22–0.81	0.01d	0.48	0.32–0.70	<0.001	0.45	0.28–0.70	<0.001
IL-21c	1.33	0.89–1.98	0.17	1.73	1.27–2.35	<0.001	2.06	1.31–3.23	0.002
IL-4 substituted for IL-21 in Marginal Cox regression model
IL-4c	1.51	1.17–1.95	0.002	1.68	1.08–2.61	0.02d	1.35	0.96–1.91	0.08

^aN=215;

^bAdjusted for age, race, BMI, smoking status, WTC exposure level, first post 9/11 FEV₁/FVC;

^cOne log₂ increase (doubling) of cytokine concentration.

^dA p value of 0.0024 was considered significant after bonferroni correction.