Table 6. Results of the multivariate binary logistic regression analysis of factors that can influence procalcitonin level on the seventh day after birth.

Variable	Crude OR (95% CI)	P value	Adjusted OR* (95% CI)	P value
VLBW	78.571 (8.045–767.344)	0.000	17.130 (1.104–265.852)	0.042
Chorioamnionitis	13.625 (2.358–78.718)	0.004	7.458 (0.458–121.396)	NS
Surfactant administration	48.182 (5.155–450.329)	0.001	2.272 (0.006–797.550)	NS
Invasive-vent application	68.125 (7.081–655.389)	0.000	13.430 (0.860–209.603)	NS
Patent ductus arteriosus	14.500 (1.628–129.143)	0.017	0.600 (0.002–220.724)	NS
Postnatal antibiotics	42.388 (5.777–311.039)	0.000	29.844 (4.011–222.040)	0.001

aOR: adjusted for VLBW, chorioamnionitis, surfactant administration, invasive-vent application, patent ductus arteriosus.

OR, odds ratio; CI, confidence interval; VLBW, very low birth weight defined as birth weight <1,500 g; NS, not significant (P≥0.05).