718: UNITED STATES TRENDS FOR AZITHROMYCIN USE IN PEDIATRIC CRITICAL ASTHMA: A MULTICENTER COHORT STUDY

Abstract

Introduction: Observation reports have suggested macrolides, such as azithromycin (AZI), may be used as immunomodulation for pediatric acute asthma exacerbations. To date, few studies have described AZI use for critical asthma (CA). We sought to estimate prescribing rates of AZI for CA and identify regional and chronologic trends using a large administrative registry. Methods: We performed a multicenter, retrospective cohort study using the Pediatric Health Information Systems registry of children 3-17 years of age with CA in the pediatric intensive care units (PICUs) of 47 United States (US) children’s hospitals from Jan 2011-Dec 2020. We excluded for alternative indications for AZI (e.g., B. pertussis infection, urethritis, pelvic inflammatory disease, and atypical pneumonia). The primary outcome was prescribing rates of AZI by hospital center and calendar year (via Joinpoint regression). Cohorts with and without AZI exposure were characterized by demographics, applied CA therapies, and routine clinical outcomes using descriptive and comparative (Chi-square and Wilcoxon rank-sum) statistics. Results: Of the 32,225 children studied, 6,641 (20.6%) were prescribed AZI with a downward trend from 31.3% in 2011 to 14.7% in 2020. A Joinpoint regression indicated a linear model was ideal (-1.7% annual slope, R2 = 0.857). Regional AZI prescribing rates by hospital center varied widely with a median of 19%, interquartile range (IQR) of 13.1% to 29.5%, and total range of 4.4% to 74.5%. Compared to children without exposure, those prescribed AZI were older (median 8.3 [IQR:5.8,11.6] vs 7.4 [5,10.9] years, P< 0.001) and more severely ill with a greater rates of bilevel positive airway pressure ventilation (13.1% vs 7.3% P< 0.001), invasive ventilation (18.8% vs 11.5%, P< 0.001), extracorporeal life support (0.5% vs 0.1%, P< 0.001), and longer median length of stay (4 [IQR:3,6] vs 3 [IQR:2,4] days, P< 0.001). Conclusions: In this multicenter study assessing children hospitalized for CA in the PICU from 47 U.S. Children’s hospitals, we observed a downward AZI prescribing trend (-1.7% annually from 31.3% in 2011 to 14.7% in 2020) and wide regional variation (range: 4.4% to 74.5% by center). Prospective clinical trials are needed to assess clinical and molecular efficacy endpoints of AZI immunomodulation in pediatric CA.