Trends In Kawasaki Disease Hospitalizations: New York State 1990-2009

Abstract

Objective: To ascertain whether Kawasaki disease (KD) hospitalization patterns have shifted in New York State. Given the known prevalence changes in other disorders which involve hypersensitivity, KD trends are of interest.Design and setting: Analysis of an administrative hospitalization database between 1990-2009 in New York was performed to determine changes in Kawasaki disease hospitalization rates and assess therapeutic interventions and clinical manifestations. For trend comparisons, hospitalization rates were also examined in 2 other disorders with hypersensitivity components: asthma and anaphylaxis.Patients: De-identified inpatient recordsMain outcome measures: Hospitalization rate changes and associated clinical features over timeResults: There was a significant increase in KD hospitalizations over the study period (negative binomial regression, p<0.0001). In patients under the age of 5 (78% of all patients), the hospitalization rate was 14.6 per 100,000 in 1990. By 2002, the hospitalization rate reached an apex of 22.5 per 100,000. This trend differed from asthma and anaphylaxis hospitalizations, which showed an overall decline, and an overall continued increase, respectively. In patients who were Asian, Pacific-Islanders, Native Hawaiian or Native Americans, there was a greater increase in KD hospitalization rates than in other patients (negative binomial regression, p=0.003). Cardiac abnormalities were coded in 6.1% of hospitalizations. Four deaths were reported, only one of which was a likely cardiac death.Conclusion: In New York State, there have been unique dynamic changes in KD hospitalization rates, which are more accentuated in the Asian population. KD continues to be an uncommon but significant disorder which results in hospitalization for young children. BACKGROUND & INTRODUCTION Kawasaki disease (KD) is a self-limited vasculitis and the leading cause of acquired heart disease in the United States among children less than 5 years of age (1). It has a particular predilection for Asian populations, which is evidenced by higher hospitalization rates for this disorder in Japan, Taiwan and Hawaii (2-4). Although the etiology of the disorder is unknown, it is felt to be most likely secondary to infection and/or an altered immunologic response. The former is suggested by the fact that KD occurs in epidemics, is self-limited, and has a seasonal presentation. The later is evidenced by the response to immunomodulatory treatment with intravenous immunoglobulin (5). As there have been dynamic changes in the incidence other diseases that relate to hypersensitivity, such as asthma and anaphylaxis (6-7), it is of interest to examine whether the KD incidence has also changed. Moreover, in this study we examined a period of time and geographic area where there have been shifts in the racial proportions in a populous American state. These racial proportions have the potential for influencing the disease incidence.