Table 2 Univariate and multivariate Cox regression analysis based on all variables for neonatal respiratory failure in NRDS patients

Ref: Ethnicity (Asian)

 Ethnicity (White)

1.23 (0.93–1.62)

0.1391

 Ethnicity (Black)

0.96 (0.69–1.33)

0.8157

 Ethnicity (Other)

0.89 (0.66–1.19)

0.4157

Gender (Male)

0.95(0.83–1.09)

0.4405

Gestational age < 28 weeks (%)

6.21(5.37–7.19)

 < 0.0001

6.63(5.59–7.85)

 < 0.0001

pH

0.12 (0.06–0.24)

 < 0.0001

0.05 (0.02–0.13)

 < 0.0001

PCO₂

1.01 (1.01–1.02)

 < 0.0001

0.99 (0.98–1)

0.0032

PO₂

0.98 (0.98–0.99)

 < 0.0001

0.96 (0.95–0.96)

 < 0.0001

WBC

0.96 (0.94–0.97)

 < 0.0001

Hb

0.94(0.91–0.96)

 < 0.0001

0.91(0.88–0.93)

 < 0.0001

PLT

1(1–1)

0.9204

Bilirubin

1(1–1)

 < 0.0001

Ref: Blood culture (not examined)

 Blood culture (negative)

6.63(3.44–12.79)

 < 0.0001

3.61(1.86–7)

 < 0.0001

 Blood culture (positive)

10.12(5.04–20.31)

 < 0.0001

3.85(1.88–7.89)

 < 0.0001

Ref: CSF culture (not examined)

 CSF culture (negative)

2(1.67–2.41)

 < 0.0001

 CSF culture (positive)

1.58(0.51–4.91)

0.4305

Infection

2.2(1.88–2.57)

 < 0.0001

1.34(1.11–1.61)

0.002

IUGR

1.12(0.87–1.44)

0.369

Neonatal anemia

1.26(1.09–1.45)

0.0017

1.16(0.97–1.39)

0.1018

Neonatal apnea

2.8(1.26–6.26)

0.0119

Neonatal asphyxia

2.31 (1.04–5.16)

0.0409

Neonatal coagulation disorders

2.86 (2.26–3.63)

 < 0.0001

Neonatal intracranial Hemorrhage

3.1(2.43–3.94)

 < 0.0001

1.42(1.08–1.86)

0.0107

Neonatal pneumonia

1.44(0.9–2.3)

0.1242

Caffeine

1.28(1.12–1.47)

 < 0.0001

0.87(0.73–1.04)

0.1377

PS

0.77(0.67–0.89)

 < 0.0001

0.76(0.65–0.89)

 < 0.0001

Parenteral nutrition

2.24(1.95–2.58)

 < 0.0001

2.13(1.78–2.54)

 < 0.0001

Respiratory support

0.59(0.51–0.67)

 < 0.0001

0.64(0.55–0.73)

 < 0.0001