Variation in antibiotic consumption in very preterm infants-a 10 year population-based study

Objectives: Wide variations in antibiotic use in very preterm infants have been reported across centres despite similar rates of infection. We describe 10 year trends in use of antibiotics and regional variations among very preterm infants in Norway.

Patients and methods: All live-born very preterm infants (<32 weeks gestation) admitted to any neonatal unit in Norway during 2009-18 were included. Main outcomes were antibiotic consumption expressed as days of antibiotic therapy (DOT) per 1000 patient days (PD), regional variations in use across four health regions, rates of sepsis and sepsis-attributable mortality and trends of antibiotic use during the study period.

Results: We included 5296 infants: 3646 (69%) were born at 28-31 weeks and 1650 (31%) were born before 28 weeks gestation with similar background characteristics across the four health regions. Overall, 80% of the very preterm infants received antibiotic therapy. The most commonly prescribed antibiotics were the combination of narrow-spectrum β-lactams and aminoglycosides, but between 2009 and 2018 we observed a marked reduction in their use from 100 to 40 DOT per 1000 PD (P < 0.001). In contrast, consumption of broad-spectrum β-lactams remained unchanged (P = 0.308). There were large variations in consumption of vancomycin, broad-spectrum β-lactams and first-generation cephalosporins, but no differences in sepsis-attributable mortality across regions.

Conclusions: The overall antibiotic consumption was reduced during the study period. Marked regional variations remained in consumption of broad-spectrum β-lactams and vancomycin, without association to sepsis-attributable mortality. Our results highlight the need for antibiotic stewardship strategies to reduce consumption of antibiotics that may enhance antibiotic resistance development.