Predictive usefulness of blood eosinophilia for hospital length of stay among children with asthma exacerbation.

BACKGROUND: The relationship between blood eosinophilia and length of hospital stay has been scarcely analyzed. OBJECTIVE: To establish the prevalence of eosinophilia in children with asthma exacerbation and to evaluate its association as a predictor of the length of hospital stay in these patients. MATERIAL AND METHODS: This retrospective cohort study analyzed data from children aged 2 to 17 years who were hospitalized for asthma exacerbation between January 2019 and December 2024 at teaching hospital. Multivariate analyses were performed to evaluate the association between blood eosinophilia (≥ 500 cells/µL) and length of hospital stay (≥ 4 days). RESULTS: Data from 225 children were analyzed; 15.1% had eosinophilia (exposed group), while the remaining 84.9% did not (non-exposed group). In the absence of pneumonia, the eosinophilia group was less likely to experience a prolonged hospital stay (RR = 0.6, P = 0.034). In this same group, eosinophils ≥ 500 cells/µL reduced the likelihood of a hospital stay ≥ 4 days (adjusted OR 0.22, P = 0.005) in the multivariate analysis. Meanwhile, age ≥ 6 years (adjusted OR 4.12, P < 0.001), moderate (adjusted OR 2.54, P = 0.016) and severe (adjusted OR 8.42, P = 0.003) Pulmonary Scores were predictors of prolonged hospital stay. CONCLUSIONS: Blood eosinophilia ≥ 500 cells/µL is associated with a shorter hospital stay. Additionally, children aged 6 years or older and those with moderate or severe exacerbations have a higher risk of prolonged hospitalization.