OBJECTIVES. Although bronchiolitis is the leading cause of hospitalization for infants, there are limited data describing the epidemiology of bronchiolitis hospitalizations, and the associated cost is unknown. Our objective was to determine nationally representative estimates of the frequency of bronchiolitis hospitalizations and its associated costs.

PATIENTS AND METHODS. We analyzed the 2002 Health Care Utilization Project-National Inpatient Sample, a federal, stratified random survey of hospital discharges. For admissions age <2 years with a discharge diagnosis of bronchiolitis (International Classification of Diseases, Ninth Revision, Clinical Modification, code 466.1), we used nationally representative weighted estimates to determine frequency and total hospital charges. Costs were estimated from reported charges by applying hospital-specific cost/charge ratios based on all-payer inpatient cost.

RESULTS. In 2002, an estimated 149000 patients were hospitalized with bronchiolitis. Frequency of hospitalizations was higher among children age <1 year of age, male gender, and nonwhite race. Mean length of stay was 3.3 days. Total annual costs for bronchiolitis-related hospitalizations were $543 million, with a mean cost of$3799 per hospitalization. Mean cost of bronchiolitis with a codiagnosis of pneumonia was $6191. In a multivariate analysis controlling for 3 confounding factors (including length of stay), cost per hospitalization was higher for children ≥1 year and lower for those in the South versus Northeast. CONCLUSIONS. Bronchiolitis admissions cost more than$500 million annually. A codiagnosis of bronchiolitis and pneumonia almost doubles the cost of the hospitalization. Inpatient health care costs of bronchiolitis are higher than estimated previously and highlight the need for initiatives to safely reduce bronchiolitis hospitalizations and thereby decrease health care costs.