The Association of Seasonality With Resource Use in a Large National Cohort of Infants With Bronchiolitis.

OBJECTIVES: Examine the degree of seasonal variation in nonrecommended resource use for bronchiolitis management subsequent to publication of the American Academy of Pediatrics (AAP) 2014 guidelines. METHODS: We performed a multicenter retrospective cohort study using the Pediatric Health Information System database, examining patients aged 1 to 24 months, diagnosed with bronchiolitis between November 2015 and November 2018. Exclusions included presence of a complex chronic condition, admission to the PICU, hospital stay >10 days, or readmission. Primary outcomes were use rates of viral testing, complete blood count, blood culture, chest radiography, antibiotics, albuterol, and systemic steroids. Each hospital’s monthly bronchiolitis census was aggregated into hospital bronchiolitis census quartiles. Mixed-effect logistic regression was performed, comparing the primary outcomes between bronchiolitis census quartiles, adjusting for patient age, race, insurance, hospitalization status, bacterial coinfection, time since publication of latest AAP bronchiolitis guidelines, and clustering by site. RESULTS: In total, 196 902 bronchiolitis patient encounters across 50 US hospitals were analyzed. All hospitals followed a similar census pattern, with peaks during winter months and nadirs during summer months. Chest radiography, albuterol, and systemic steroid use were found to significantly increase in lower bronchiolitis census quartiles, whereas rates of viral testing significantly decreased. No significant variation was found for complete blood count testing, blood culture testing, or antibiotic use. Overall adherence with AAP guidelines increased over time. CONCLUSIONS: Resource use for patients with bronchiolitis varied significantly across hospital bronchiolitis census quartiles despite adjusting for potential known confounders. There remains a need for greater standardization of bronchiolitis management.