Childhood asthma in the Bronx, NY; the impact of pollutants on length of hospital stay

Objective: The length of hospital stay (LOS) is a proxy of asthma exacerbation severity and healthcare cost. The study aims to estimate the effect of ambient air pollution on pediatric asthma LOS in the Bronx, NY. Methods: A total of 1,920 children admitted to the hospital in Bronx, NY due to asthma during 2017–2019 period were included in the study. Demographic and clinical parameters were obtained from medical records. Daily ozone (O₃) and fine particulate matter (PM_2.5) measurements were obtained from local air quality networks. Poisson regression adjusting for gender, age, weight status, respiratory infections including influenza, and ambient temperature was applied to determine whether there was an association of air pollution with length of hospital stay. Results: The mean LOS varied by age, sex, weight status, influenza vaccination status, respiratory viral panel (RVP) results, asthma controller use, and asthma classification. After controlling for these factors in Poisson regression, the mean LOS increased up to 10.62% (95%CI: 0.78–21.41; p = 0.03) for an increase of 10 μg/m³ of PM_2.5 exposure on admission day, and 3.90% (95%CI = 0.06–7.88; p = 0.05) for an increase of 10 ppbv of O₃ concentration during the previous day. Conclusion: Ambient particulate and ozone pollution is associated with lengthier hospital stays for pediatric asthma, potentially indicating more severe asthma exacerbations.