Risk factors for progression to bronchitis or pneumonia in hospitalized children with human rhinovirus infection: a retrospective cohort study using machine learning

Background: Human rhinovirus (HRV) is a leading cause of acute respiratory infections and hospitalization in children. However, risk factors for progression to bronchitis vs. pneumonia remain incompletely characterized. Objective: This study aimed to identify and distinguish independent predictors for these outcomes using a machine learning approach. Methods: A retrospective cohort study was conducted among hospitalized children with HRV infection at the First Affiliated Hospital of Ningbo University. A two-stage feature selection method (Random Forest and LASSO) was used, followed by multinomial logistic regression to quantify associations with progression to bronchitis or pneumonia. Results: : 0.83-0.96). Conclusion: Bronchitis progression is primarily associated with airway obstruction, whereas pneumonia is linked to more complex clinical scenarios, including prior medication, co-infections, and coagulopathy. These findings can improve early risk stratification and guide targeted interventions.