Table 3.

Regression coefficients (β) and p-values of the multiple regression models for eNO parameters in age group 12–18 years

	Interceptβ	Age			Gender			Height			BMI			Regions
		β	p-value		β	p-value		β	p-value		β	p-value		β	p-value	R 2	R2boot
FeNO50	2.396	-0.010	0.638		-0.123	< 0.001		0.003	< 0.05		-0.026	0.195		0.023	< 0.001	0.023	0.022
FeNO200	0.501	-0.115	0.052		-0.077	0.187		0.009	< 0.001		-0.082	0.142		-	-	0.043	0.040
CaNO	1.740	-0.050	< 0.05		-0.005	0.929		-0.008	0.896		0.038	0.514		-	-	0.017	0.014

The R² is the unadjusted coefficient of determination of the models and R² boot is the corresponding optimism- corrected R² values as estimated by bootstrapping