No Improvement in Length of Hospital Stay, Readmission With Azithromycin for Pediatric Asthma

Smog over New York City Skyline, air pollution
Smog over New York City Skyline, air pollution
Researchers found data from a 10-year retrospective cohort study that showed azithromycin therapy for children with asthma was not associated with hospital readmission or length of stay.

Azithromycin therapy has not demonstrated a significant ability to reduce either hospital length of stay or readmission rates among children with asthma, according to a study recently published in the Journal of Asthma.

This retrospective cohort study included 5335 participants with asthma, all of whom were under 18 years of age and who did not have concurrent infection. The study took place at an urban children’s hospital between 2002 and 2011. Azithromycin therapy was administered within 48 hours of hospitalization to 3% (n=174) of participants. Hospital length of stay constituted the primary outcome, while 7-, 30-, and 90-day asthma-related readmission rates constituted the secondary outcomes. The association between azithromycin therapy and hospital length of stay was examined through the use of multivariable linear regression models with adjustments for potential confounders.

Related Articles

The median length of stay was 2.3 (interquartile range [IQR] 1.8-3.1) days, and there was a 9% asthma-related readmission rate in the 90-day period following discharge. The majority of individuals had a length of stay <8.2 days. Those given azithromycin therapy remained in the hospital 20% (11 hours) longer (adjusted beta coefficient for log-transformed length of stay, 0.18 [95% CI, 0.11-0.26]) than those excluded from this treatment, though this difference was not clinically relevant. There was no significant association found between azithromycin therapy and 90-day asthma-related readmission rates (adjusted odds ratio 0.89 [95% CI, 0.46-1.72]). Readmission rates were 0.9% for 7 days, 4% for 30 days, and 9% for 90 days.

Limitations to this study include the use of a single-center, low generalizability due to high asthma rates in the Bronx, New York, potential for missed readmissions, a retrospective study design, the potential for indication bias and unmeasured confounders, the use of ICD-9 billing classification to identify participants, a lack of exclusion of other populations that could cause overlap, and a limitation of azithromycin therapy exposure to the first 48 hours of admission.

The study researchers conclude that “azithromycin therapy was not associated with a clinically relevant difference in hospital [length of stay] or statistically significant difference in readmission rates for children hospitalized with asthma. Further studies, including prospective randomized controlled trials, are needed to address whether macrolide therapy affects clinical outcomes for acute asthma exacerbations in children.”


Douglas LC, Choi J, Esteban-Cruciani N. Azithromycin treatment in children hospitalized with asthma: a retrospective cohort study [published online April 1, 2019]. J Asthma. doi: 10.1080/02770903.2019.1590590