Table 4: Univariate analysis of various risk factors for infections with ESBL-producing organisms.

VariableNeonates with acquisition of infections with ESBL-producing organisms
( )
Neonates with acquisition of infections with non-ESBL-producing organisms
( )
valueRelative risk
(95% CI)

Birthweight (g)1088 (825)2253 (745)0.001
Gestational age (weeks)29 (3.24)37 (4.15)0.001
Birthweight < 1000 g (ELBW)3 (38)2 (11)0.0285.04
(0.94–150.82)
Preterm7 (88)13 (33)0.0050.11
(0.01–0.79)
Perinatal asphyxia7 (88)16 (41)0.0177.30
(0.97–54.83)
Mechanical ventilation > 7 days5 (63)10 (26)0.0410.28
(0.08–1.03)
Anemia3 (38)4 (10)0.0495.25
(0.67–43.39)
Metabolic acidosis3 (38)3 (8)0.0214.10
(1.30–12.91)
Respiratory distress syndrome5 (63)3 (8)0.0018.13
(2.42–27.32)
Central venous catheter duration (days)12 (5.4)2.4 (4.3)0.001
PICC duration (days)29 (13–35)7 (0–12)0.006
TPN duration (days)26 (16–31)7 (0–12)0.001
Duration of hospital stay (days)61 (39–91)19 (11–21)0.002
Duration of level 3 stay (days)54 (35–77)11 (7–22)0.001

ESBL: extended-spectrum beta-lactamase; CI: Confidence interval; PICC: peripherally inserted central venous catheter; TPN: total parenteral nutrition.
Univariate analysis of risk factors: only those with value < 0.05 are shown.
Data are expressed as numbers (%), mean (standard deviation), and median (interquartile range).