Table 4. Results of the multivariate binary logistic regression analysis of factors that can influence procalcitonin level on the third day after birth.

Variable	Crude OR (95% CI)	P value	Adjusted OR* (95% CI)	P value
Gestational age (wk)	0.983 (0.972–0.996)	0.007	0.990 (0.971–1.010)	NS
Male sex	0.586 (0.345–0.995)	0.048	0.638 (0.354–1.152)	NS
Surfactant administration	3.067 (1.294–7.270)	0.011	0.553 (0.134–2.287)	NS
Vent application	4.176 (2.428–7.182)	0.000	2.596 (1.464–4.605)	0.001
Noninvasive vent application	3.508 (2.043–6.022)	0.000	0.929 (0.185–4.675)	NS
Postnatal antibiotics	42.388 (5.777–311.039)	0.000	29.844 (4.011–222.040)	0.001
C-reactive protein	1.324 (1.060–1.653)	0.013	1.289 (1.012–1.640)	0.039

OR, odds ratio; CI, confidence interval; GA, gestational age; VLBW, very low birth weight; NS, not significant (P≥0.05).

^*aOR: adjusted for preterm birth, VLBW, prenatal antibiotics, surfactant administration, serum C-reactive protein level, and white blood cell count.