Association Between Antibiotic Overexposure and Adverse Outcomes in Very-Low-Birth-Weight Infants Without Culture-Proven Sepsis or Necrotizing Enterocolitis: A Multicenter Prospective Study

OBJECTIVES: To explore the associations between higher antibiotic use rates (AURs) and adverse outcomes in very-low-birth-weight (VLBW) infants without culture-proven sepsis or necrotizing enterocolitis (NEC) in a multicenter of China. METHODS: A prospective cohort study was performed on VLBW infants admitted to 24 neonatal intensive care units from January 1, 2018, to December 31, 2018. AUR was calculated as calendar days of antibiotic therapy divided by total hospital days. The composite primary outcome was defined as mortality or severe morbidity, including any of the following: severe neurologic injury, bronchopulmonary dysplasia (BPD), and stage 3 or higher retinopathy of prematurity. RESULTS: A total of 1,034 VLBW infants who received antibiotics without culture-proven sepsis or NEC were included in this study. The overall AUR of eligible VLBW infants was 55%, and the AUR of each eligible VLBW infant ranged from 3 to 100%, with a median of 56% (IQR 33%, 86%). After generalized propensity score and logistic regression analysis of 4 groups of VLBW infants with different AUR range, infants in the higher quartile AUR, (Q3, 0.57~0.86) and (Q4, 0.87~1.00), had higher odds of composite primary outcome (adjusted OR: 1.81; 95% CI: 1.23–2.67; adjusted OR 2.37; 95% CI: 1.59–3.54, respectively) and BPD (adjusted OR: 3.09; 95% CI: 1.52–6.57; adjusted OR 3.17; 95% CI: 1.56–6.57, respectively) than those in the lowest AUR (Q1). CONCLUSIONS: Antibiotic overexposure in VLBW infants without culture-proven sepsis or NEC was associated with increased risk of composite primary outcome and BPD. Rational empirical antibiotic use in VLBW infants is urgently needed in China.