Table 3– Associations between exhaled nitric oxide fraction (F_eNO), total NO₂⁻/NO₃⁻ and ratio levels in exhaled breath condensate (EBC) with eosinophilic asthma and age at onset

	EBC NO₂⁻/NO₃⁻ level μmol per mg proteins^#				F_eNO level ppb^¶				(NO₂⁻+NO₃⁻)/NO ratio level⁺
	n	GM	95% CI	p-value	n	GM	95% CI	p-value	n	Mean	95% CI	p-value
Eosinophilic asthma
No	162	1.97	1.61–2.41		162	15.4	13.7–17.2		162	0.25	0.16–0.34
Yes	93	2.54	1.98–3.26	0.12	93	22.0	19.0–25.5	0.0002	93	0.30	0.22–0.39	0.4
Age at onset
0–4 years	87	2.49	1.93–3.21		87	17.7	15.1–20.6		87	0.33	0.22–0.43
4–16 years	94	2.09	1.60–2.75	0.3^§	94	17.8	15.3–20.7	0.7^§	94	0.25	0.14–0.35	0.4^§
>16 years	56	1.99	1.38–2.87		56	16.8	13.6–20.8		56	0.26	0.11–0.41
Model adjusted for all covariates
Eosinophilic asthma
No	157	1.79	1.35–2.37		162	16.8	14.6–19.4		162	0.20	0.09–0.32
Yes	92	2.30	1.66–3.18	0.13	93	23.9	20.2–28.3	<0.0001	93	0.27	0.14–0.40	0.3
Age at onset
0–4 years	84	2.26	1.60–3.20		87	18.8	15.6–22.6		87	0.30	0.17–0.43
4–16 years	93	1.91	1.37–2.67	0.15^§	94	19.4	16.3–23.1	0.9^§	94	0.21	0.08–0.34	0.15^§
>16 years	56	1.59	1.02–2.00		56	18.4	14.6–23.3		56	0.17	0.01–0.34

GM: geometric mean. ^#: adjusted for age, sex, smoking, ambient ozone concentration, asthma and centre; ^¶: adjusted for age, sex, smoking, height, asthma and centre (generalised estimating equation regression methods); ⁺: adjusted for age, sex, smoking, asthma and centre; ^§: p-value for trend.