Table 3.

Risk factors and their association with common and severe respiratory outcomes in all subjects (n = 126).

Risk factors	Common outcomes			Severe outcomes
	n = 101			n = 37
	OR	CI	p-value	OR	CI	p-value
BPDa	0.57	(0.22-1.49)	0.249	1.20	(0.54-2.66)	0.659
Known risk factors for BPD
Gestational age, per week	1.04	(0.89-1.22)	0.605	0.94	(0.82-1.08)	0.375
Male sex	1.25	(0.52-3.00)	0.625	1.02	(0.47-2.22)	0.953
Birthweight, per kg	1.36	(0.56-3.29)	0.493	0.70	(0.32-1.51)	0.362
Chorioamnionitisb	1.58	(0.56-4.44)	0.387	1.55	(0.68-3.52)	0.295
PDAc	1.65	(0.51-5.32)	0.402	0.56	(0.21-1.52)	0.253
PIPd	1.10	(0.92-1.33)	0.292	1.24	(1.05-1.47)	0.012
Factors of perinatal adaption
Cord blood pHe	1.98	(0.41-9.48)	0.393	4.37	(1.4-13.61)	0.011
APGAR score at 10 min.f	1.05	(0.74-1.49)	0.783	1.55	(1.14-2.12)	0.006
CRIB-score	0.93	(0.82-1.05)	0.232	1.14	(1.01-1.28)	0.024
Environmental risk factors
Contact to other childreng	4.71	(1.77-12.56)	0.002	1.30	(0.59-2.90)	0.516
Maternal atopy	1.52	(0.41-5.66)	0.532	0.82	(0.27-2.46)	0.727
smoking in pregnancy	1.41	(0.29-6.79)	0.672	1.58	(0.48-5.20)	0.450

In the table are shown: Odds ratio (OR), calculated by univariable logistic regression, defining the increased odds of having the respective outcome with the respective risk factor present; 95% Confidence interval (CI) and p-value.

^a BPD was defined as in the consensus guidelines (2)

^b Chorioamnionitis was verified by histological findings of the placenta

^c PDA = haemodynamic relevant patent ductus arteriosus

^d PIP = maximum peak inspiratory pressure

^e Cord blood pH = arterial chord blood pH: 1 defined as < 7.15 and 0 defined as > 7.15

^f comparable results were obtained for APGAR-scores at 1 and 5 minutes

^g Contact to other children = having siblings or going to a nursery care institution regularly