Impact of NICE clinical guidelines for prevention and treatment of neonatal infections on antibiotic use in very preterm infants in England and Wales: an interrupted time series analysis.

Objective: To assess the impact of publication of UK National Institute for Health and Care Excellence (NICE) guidelines on the prevention and treatment of early-onset infections (EOIs) in neonates (clinical guideline 149 (CG149), published in 2012, and its 2021 update (NG195) on antibiotic use in very preterm infants.

Design: Interrupted time series analysis using data from the National Neonatal Research Database.

Setting: Neonatal units in England and Wales.

Participants: Infants born at 22-31 weeks' gestation from 1 January 2010 to 31 December 2022 and survived to discharge.

Interventions: Publication of CG149 (August 2012) and NG195 (April 2021).

Main outcome measures: Measures of antibiotic use, aggregated by month of birth: antibiotic use rate (AUR), the proportion of care days in receipt of at least one antibiotic; percentage of infants who received ≥1 day of antibiotics on days 1-3 for EOI and after day 3 for late-onset infection (LOI); percentage who received ≥1 prolonged antibiotic course ≥5 days for EOI and LOI.

Results: 96% of infants received an antibiotic during inpatient stay. AUR declined at publication of CG149, without further impact at NG195 publication. There was no impact of CG149 on the underlying trend in infants receiving ≥1 day antibiotics for EOI or LOI, but post-NG195 the monthly trend began to decline for EOI (-0.20%, -0.26 to -0.14) and LOI (-0.23%, -0.33 to -0.12). Use of prolonged antibiotic courses for EOI and LOI declined at publication of CG149 and for LOI this trend accelerated post-NG195.

Conclusions: Publications of NICE guidance were associated with reductions in antibiotic use; however neonatal antibiotic exposure remains extremely high.