Azithromycin for Pediatric Critical Asthma: A Multicenter Retrospective Cohort Study

OBJECTIVES To characterize the prescribing trends and clinical outcomes related to azithromycin (AZI) among children hospitalized for critical asthma (CA). METHODS We performed a multicenter, retrospective cohort study using the Pediatric Health Information Systems registry of children 3 to 17 years of age hospitalized in a PICU for CA from January 2011 to December 2022. We excluded for alternative indications for AZI (eg, atypical pneumonia, B. pertussis infection, acute otitis media, acute sinusitis, pharyngitis/tonsillitis, and urethritis). The primary outcome was AZI prescribing rate by hospital and calendar year (trends assessed by Joinpoint regression). Cohorts with and without AZI exposure were further characterized by demographics, CA treatments, and inpatient outcomes using descriptive and comparative (ie, χ2 and Wilcoxon rank tests) statistics. RESULTS Of the 47 797 children studied, 9901 (20.7%) were prescribed AZI with a downward annual trend noted from 34.7% in 2011% to 12.4% in 2022 (−1.7% per year, R2 = 0.91). Median institutional AZI prescribing rate was 19.2% (interquartile range IQR 11.7%–28%; total range 5.6%–60%). Compared with children not prescribed AZI, those prescribed AZI were older (median 8.3 IQR 5.7–11.6 vs 7.3 4.9–10.8 years, P .001) and experienced a more severe clinical trajectory with greater rates of bilevel positive airway pressure ventilation (19.7% vs 12.6%, P .001), invasive ventilation (22.1% vs 13.5%, P .001), extracorporeal life support (0.8% vs 0.1%, P .001), and median length of stay (4 IQR 3–6 vs 3 IQR 2–4 days, P .001). CONCLUSIONS Between 2011 and 2022, 20.7% of children hospitalized for CA were prescribed AZI notwithstanding the absence of trial-derived efficacy or safety data for this indication and population.