摘要：Objectives. We sought to compare the burden of hospitalizations associated with rotavirus gastroenteritis (RGE) in children younger than 5 years in US Medicaid and non-Medicaid populations in 2000 and 2003. Methods . We used the Kids' Inpatient Database (KID) to examine the burden of RGE-associated hospitalizations in terms of numbers and rates of hospitalizations, lengths of stay, and hospital charges. Two indirect methods were also used to estimate RGE-associated hospitalizations, because rotavirus testing is not routinely performed. Results . Approximately 40% of children younger than 5 years were enrolled in Medicaid in 2003, but this population accounted for nearly 50% of all RGE-associated hospitalizations and 60% of total charges. Children enrolled in Medicaid had significantly greater hospitalization rates, average lengths of stay, and average charges per stay than did those not enrolled. Conclusions . Although RGE affects all socioeconomic groups, the Medicaid population accounted for a disproportionate number of the hospitalizations. With the inclusion of rotavirus vaccines in the pediatric immunization schedule, it is important that US children, especially those enrolled in Medicaid programs, are vaccinated to reduce the burden of RGE. Rotavirus is the leading cause of severe acute gastroenteritis among children. By the age of 5 years, nearly every child is infected with rotavirus at least once. 1 – 3 Although many cases of rotavirus gastroenteritis (RGE) are mild, some can be severe. Recent studies have estimated that in the United States, RGE causes 55 000 to 70 000 hospitalizations, 205 000 to 272 000 emergency department visits, and 410 000 physician visits each year, 3 , 4 with total RGE-related direct and indirect costs estimated at approximately $1 billion annually. 5 , 6 Rotavirus accounts for 4% to 5% of all hospitalizations and 30% of hospitalizations for watery diarrhea among children younger than 5 years, 7 – 9 and the annual direct costs of RGE-associated hospitalizations are estimated at $175 to $198 million. 5 , 6 In the United States, yearly epidemics of rotavirus disease occur from late fall to early spring, with the peak of disease varying by region. 7 , 8 , 10 , 11 In the Southwest, the peak epidemic rotavirus season is from November to December; it then travels sequentially across the United States from west to east, concluding in April to May in the northeast. 10 Because naturally acquired rotavirus infections provide protection against future severe RGE, hospitalizations because of RGE are more likely to occur in children younger than 5 years. 10 Because many physicians do not test for rotavirus routinely, the rotavirus-specific International Classification of Diseases, 9th Revision, Clinical Modification ( ICD-9-CM ), 12 code 008.61 is underused and the incidence of this disease is generally underreported. 8 , 13 – 15 Therefore, indirect methods, such as the winter residual or the proportional methods, are commonly used to estimate the burden of hospitalizations associated with RGE based on hospitalizations for acute gastroenteritis. 4 , 7 , 8 Limited data suggest that children from disadvantaged socioeconomic backgrounds are at greater risk of hospitalization from gastroenteritis, including viral gastroenteritis, compared with the general population. 16 – 18 Medicaid, a health program jointly funded by the states and federal government and administered by each state, is designed to support individuals and families with low incomes and limited resources. One recent study found that children younger than 24 months who were enrolled in Medicaid or without insurance were at increased risk of hospitalization caused by rotavirus. 17 Although children enrolled in Medicaid account for a substantial proportion of the US population of children, the burden of RGE-associated hospitalization in this population is not known. For our study, we consolidated data from various sources to estimate and compare the burden of RGE-associated hospitalizations among children younger than 5 years in the Medicaid and non-Medicaid populations in 2000 and 2003. Because of the recent availability of rotavirus vaccines to prevent RGE, 19 , 20 we also provide a baseline assessment of the potential impact of the rotavirus immunization program being implemented in the United States. 21 , 22
