Reducing unnecessary antibiotic use in the neonatal intensive care unit (SCOUT): a prospective interrupted time-series study

Background: Antibiotics are used frequently in the neonatal intensive care unit. We aimed to inform antibiotic stewardship strategies in a level 3 neonatal intensive care unit by surveillance and assessment of all antibiotic use during a 14-month period, identifying scenarios where antibiotic use can be reduced, and implementing interventions while monitoring safety.

Methods: The SCOUT study is an observational study in the level 3 neonatal intensive care unit at Parkland Hospital, Dallas, TX, USA. All antibiotic use in infants admitted to the neonatal intensive care unit between March 1, 2012, and Nov 30, 2012 (9 months), was monitored and analysed. After the baseline period (Oct 3, 2011, to Nov 30, 2012), continuation of empirical antibiotic therapy for ruled-out sepsis courses beyond 48 h, pneumonia, and "culture-negative" sepsis were selected as targets for antibiotic stewardship interventions. During the intervention period (Oct 1, 2013, to June 30, 2014), empirical antibiotic therapy was set to discontinue after 48 h in the electronic medical record and the duration of therapy for pneumonia and culture-negative sepsis was limited to 5 days. Antibiotic use, defined as days of therapy per 1000 patient-days, was compared between the baseline and intervention periods. The primary outcome was the change in total antibiotic days of therapy per 1000 patient-days between the baseline and intervention periods. Safety outcomes measured were instances in which infants received 5 or more days of therapy and subsequently had antibiotic therapy reinstituted within 14 days for any indication; a composite of late-onset sepsis, necrotising enterocolitis (modified Bell stage ≥2), or death in infants 32 weeks' gestation or younger; prevalence of multidrug-resistant organism colonisation; and length of hospital stay.

Findings: 2502 infants were admitted to the neonatal intensive care unit during the two study periods (1607 in the baseline period and 895 in the intervention period). Antibiotic use declined from 343·2 days of therapy per 1000 patient-days during the baseline period to 252·2 days of therapy per 1000 patient-days in the intervention period (p<0·0001), representing an overall decrease of 27%. No difference in safety outcomes was observed between the intervention and baseline periods.

Interpretation: Thorough assessment of antibiotic consumption in a neonatal intensive care unit can inform high-yield stewardship targets tailored to the individual centre. Effective interventions to reduce antibiotic use can then be designed and implemented in a collaborative manner.

Funding: The Gerber Foundation.