Azithromycin for Critically Ill Children With Bronchiolitis: A U.S. Pediatric Health Information Systems Registry...

To estimate prescribing rates for azithromycin as immunomodulation among critically ill children hospitalized for acute bronchiolitis and identify institutional and chronological prescribing variation.

Multicenter, observational, retrospective cohort study using the Pediatric Health Information Systems registry from 2013 to 2022.

Forty-seven PICUs in the United States.

Critically ill children 0-3 years old hospitalized for acute viral bronchiolitis excluding those prescribed azithromycin with alternative indication (i.e., concurrent Bordetella pertussis infection, urethritis, atypical pneumonia, acute upper respiratory infections, and asthma-related diagnoses).

Azithromycin prescription during hospitalization.

A total of 82,677 children met study criteria of which 3,161 (3.8%) were prescribed azithromycin. Mean (± sd ) center-specific azithromycin prescribing rates exhibited a multilinear decreasing trend (joinpoint breakpoint noted in 2017) going from 4.0% ± 4.6% in 2013 to 2.2% ± 0.8% in 2022 (-0.7%/yr). The median institutional azithromycin prescribing rate was 2.8% (interquartile range [IQR], 1.8-3.9%; total range, 1.2-24.3%). Compared with those not prescribed azithromycin, receipt of azithromycin was associated with the following: older age (median, 10 mo [IQR, 3.2-20.3 mo] vs. 7.8 mo [IQR, 2.9-15.2 mo]; p < 0.001); receiving corticosteroids (57.1% vs. 38.1%; p < 0.001) or continuous albuterol (35.9% vs. 22.4%; p < 0.001); use of noninvasive respiratory support (13.4% vs. 9.7%; p < 0.001) or invasive ventilation (35.9% vs. 22.4%; p < 0.001); and extracorporeal life support (0.5% vs. 0.1%; p < 0.001).

In this 2013-2022, U.S. multicenter registry-based cohort study, the azithromycin prescribing rate for critically ill children with bronchiolitis was 3.8%. Exposure varied by institution, patient age, and revealed a decreasing trend over the last decade.