(1216) Shifting Trends in Lower Respiratory Tract (LRT) Diagnoses and Bronchodilators in Children < 2 Years

Introduction: Bronchiolitis shares clinical features with asthma and pneumonia, which can complicate diagnosis and management. Recent recommendations to avoid bronchodilators in bronchiolitis may be impacting utilization and subsequent diagnoses. We aimed to evaluate 1) trends in the proportion of LRT diseases diagnosed as bronchiolitis and 2) trends in bronchodilator use over time among young children presenting to children’s hospitals.

Methods: We performed a retrospective cohort study from 2010 through 2022 using the Pediatric Health Information Systems database. We included encounters for children < 2 years with an ICD 9/10 discharge diagnosis of bronchiolitis, asthma/reactive airway disease, or pneumonia. We excluded children with chronic complex conditions.

The primary outcome was the proportion of LRT diseases diagnosed as bronchiolitis (termed the Bronchiolitis Quotient (BQ)) over the study period. The secondary outcome was temporal trends in bronchodilators in patients with any of the 3 diagnoses. We performed a sub-analysis of PICU encounters. Descriptive statistics were used to assess population characteristics.

Results: 1,124,435 encounters were included in this study (107,145 PICU admissions). From 2010 through 2022, the median (IQR) BQ increased from 0.52 (0.45, 0.60) to 0.75 (0.70, 0.82) for all hospital encounters and 0.37 (0.29, 0.46) to 0.53 (0.48, 0.57), p< 0.05 for PICU encounters. Bronchodilator use declined in both settings from 50.2% to 30.4% for the full cohort and 74.8% to 62.3% for PICU encounters.

Conclusions: From 2010 to 2022, the proportion of hospital-based respiratory encounters diagnosed as bronchiolitis has increased while asthma diagnoses have declined among young children. Concurrently, bronchodilator use across the 3 diagnoses has decreased. One potential mechanism of these observed changes is fewer albuterol “trials”, leading to decreased misdiagnosis of asthma. In the PICU, bronchodilators are used more frequently while bronchiolitis is diagnosed less commonly. Future studies are warranted to better understand these prescribing patterns and assess the clinical utility of bronchodilators in critical bronchiolitis.