Table 4.

Logistic regression of the association of the presence of low FEF_25-75 with low lung function measurement in participants without AL

Variable	Univariate			Multivariate*
	OR	95% CI	P value	OR	95% CI	P value
Age	1.004	0.991 to 1.018	0.55
Pack-years	1.009	1.003 to 1.015	0.002	0.988	0.971 to 1.005	0.168
Smoking status†
Current smokers	1.340	0.983 to 1.827	0.064
Sex‡
Female	1.383	1.016 to 1.883	0.039	33.225	8.194 to 134.723	<0.001
FEV1 z-score	0.136	0.100 to 0.185	<0.001	0.001	0.00008 to 0.005	<0.001
FEV1/FVC z-score	0.043	0.027 to 0.068	<0.001	0.00001	0.000001 to 0.0003	<0.001
FVC z-score	0.449	0.377 to 0.536	<0.001

This tables demonstrate the logistic regression of the association of the presence of low FEF_25-75 with low lung function measurements in participants without AL (n=651 (those normal FEF_25-75 n=316 vs those with low FEF_25-75 n=335)).

Low FEF_25-75 was defined by z-score<−0.8435.

Statistically significant p values are written in bold.

*The multivariate regression model showed a Nagelkerke R²=0.942 and Hosmer-Lemeshow p value=0.999.

†The reference category was ex-smokers.

‡The reference category was male.

AL, airflow limitation; BMI, body mass index; FEF25-75, forced expiratory flow between 25% and 75% of vital capacity; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.