Day of Illness and Outcomes in Bronchiolitis Hospitalizations

Abstract

BACKGROUND: Bronchiolitis is often described to follow an expected clinical trajectory, with a peak in severity between days 3 and 5. This predicted trajectory may influence anticipatory guidance and clinical decision-making. We aimed to determine the association between day of illness at admission and outcomes, including hospital length of stay, receipt of positive-pressure ventilation, and total cough duration. METHODS: We compiled data from 2 multicenter prospective studies involving bronchiolitis hospitalizations in patients <2 years. Patients were excluded for complex conditions. We assessed total cough duration via weekly postdischarge phone calls. We used mixed-effects multivariable regression models to test associations between day of illness and outcomes, with adjustment for age, sex, insurance (government versus nongovernment), race, and ethnicity. RESULTS: The median (interquartile range) day of illness at admission for 746 patients was 4 (2–5) days. Day of illness at admission was not associated with length of stay (coefficient 0.01 days, 95% confidence interval [CI]: −0.05 to 0.08 days), positive-pressure ventilation (adjusted odds ratio: 1.0, 95% CI: 0.9 to 1.1), or total cough duration (coefficient 0.33 days, 95% CI: −0.01 to 0.67 days). Additionally, there was no significant difference in day of illness at discharge in readmitted versus nonreadmitted patients (5.9 vs 6.4 days, P = .54). The median cough duration postdischarge was 6 days, with 65 (14.3%) patients experiencing cough for 14+ days. CONCLUSIONS: We found no associations between day of illness at admission and outcomes in bronchiolitis hospitalizations. Practitioners should exercise caution when making clinical decisions or providing anticipatory guidance based on symptom duration.