Kawasaki syndrome hospitalizations and associated costs in the United States

OBJECTIVES: To describe the epidemiologic characteristics of patients hospitalized with Kawasaki syndrome (KS) and estimate associated costs in the United States, using a large national hospital discharge dataset. METHODS: Hospitalization discharge records with KS for 1997 through 1999 for U.S. residents <18 years of age were selected from Solucient's hospital discharge records. These records are collected from most of the self-governing children's hospitals and approximately one-third of short-term, non-federal general hospitals in the United States. RESULTS: A total of 7,431 hospital discharges with a KS diagnosis were identified; 2,270 of the discharges were in 1997, 2,700 in 1998, and 2,461 in 1999. Boys comprised 60.0% of the discharges, and 76.4% of discharges were among children ages <5 years. For the 44 states and the District of Columbia with at least one hospital reporting KS, the average annual KS hospitalization rate was 10.2 per 100,000 children ages <5 years. The KS hospitalization rate for boys (12.0 per 100,000) was higher than that for girls (8.3 per 100,000) (risk ratio 1.45; 95% confidence interval 1.37, 1.52). Extrapolation to the U.S. population showed an estimated average annual KS hospitalization rate of 21.6. The median KS hospitalization cost for children <5 years of age during the study period was $6,169 US dollars. CONCLUSIONS: The KS hospitalization rate was consistent with that of previous U.S. studies, although the extrapolated rate may be an overestimation. The median hospitalization cost for KS was higher than that for respiratory syncytial virus-associated bronchiolitis and diarrheal diseases. Large hospitalization datasets can be used to monitor the occurrence of KS in the United States.