Table 4.

Multivariable stepwise forward analysis

Chlamydia	Total population
	Univariate			Multivariable
	OR	95%CI	P-value	OR	95%CI	P-value
Age	1.02	1.01–1.03	< 0.0001	1.02	1.00–1.03	0.001
Gender (M)	0.69	0.46–1.03	0.067	0.59	0.38–0.90	0.015
FENO	0.79	0.64–0.99	0.040	0.76	0.60–0.96	0.019

Variables independently associated to positivity to Chlamydia (IgA−/IgG + and IgA + /IgG +)