Table 3.

Aassociation between the main variables of interest and DLCO by a multi stepwise linear regression analysis.

	Regression coefficient	P-value
Gestational age	0.52	0.000
Birth weight (kg)	0.07	0.76
Sex	0.13	0.14
Mechanical ventilation duration (days)	0.11	0.25
CPAP duration (days)	0.17	0.12
Breastfeeding duration (months)	0.13	0.16
Body mass index at follow-up visit (kg/m2)	0.14	0.12

CPAP, continuous positive airway pressure.

The statistical significance level is p < 0.05 and it is indicated in bold.