摘要：Objectives. We examined the costs of treating American Indian adults with diabetes within the Indian Health Service (IHS). Methods. We extracted demographic and health service utilization data from the IHS electronic medical reporting system for 32 052 American Indian adults in central Arizona in 2004 and 2005. We derived treatment cost estimates from an IHS facility–specific cost report. We examined chronic condition prevalence, medical service utilization, and treatment costs for American Indians with and without diabetes. Results. IHS treatment costs for the 10.9% of American Indian adults with diabetes accounted for 37.0% of all adult treatment costs. Persons with diabetes accounted for nearly half of all hospital days (excluding days for obstetrical care). Hospital inpatient service costs for those with diabetes accounted for 32.2% of all costs. Conclusions. In this first study of treatment costs within the IHS, costs for American Indians with diabetes were found to consume a significant proportion of IHS resources. The findings give federal agencies and tribes critical information for resource allocation and policy formulation to reduce and eventually eliminate diabetes-related disparities between American Indians and Alaska Natives and other racial/ethnic populations. Health disparities between American Indians and Alaska Natives and other racial/ethnic populations are well documented. 1–8 Some of the most notable disparities concern diabetes-related morbidity and mortality. 9–21 American Indians and Alaska Natives have the highest prevalence of diabetes among all racial/ethnic groups in the United States. They are 2.3 times more likely to be diagnosed with diabetes than is the general US population, and in 2004 the prevalence of diabetes was 16.3% among American Indians and Alaska Natives aged 20 years and older. 16 Mortality attributable to diabetes is 3 to 4 times higher among American Indians and Alaska Natives than among other racial/ethnic groups. 1,16,20,21 Diabetes is the strongest predictor of cardiovascular disease (CVD) among American Indians, 15,22,23 and coronary heart disease appears to be fatal more often among American Indians and Alaska Natives than among other populations. 15,17,19 American Indians and Alaska Natives have the highest rate of premature deaths from heart disease among all racial/ethnic groups, 19 with a rate nearly 2.5 times the rate for Whites. Among American Indians and Alaska Natives, 36.0% of deaths from heart disease occur among persons younger than 65 years. 19 The Indian Health Service (IHS) provides health services for nearly 2 million American Indians and Alaska Natives, both directly though IHS clinics and hospitals and indirectly through contracts and compacts with tribes and through funding for urban Indian health programs. 24 The medical needs of American Indians and Alaska Natives with diabetes are complex because diabetes in this population is characterized by early onset of type 2 diabetes and high rates of comorbidities (e.g., heart disease, kidney failure, lower-limb amputation). 9–18,25,26 To address these needs the Special Diabetes Program for Indians provides funds to IHS and tribal organizations for diabetes prevention and treatment programs. 27 Since the program's implementation in 1997, intermediate clinical outcomes (e.g., blood glucose, blood pressure, cholesterol levels) among American Indians and Alaska Natives with diabetes have improved, 28 and the incidence of diabetes-related end-stage renal disease has decreased. 9 However, stubbornly high rates of diabetes, related complications, and premature mortality among American Indians and Alaska Natives underscore the need to enhance prevention and treatment strategies. It is critical to understand health service utilization and treatment costs for American Indians and Alaska Natives with diabetes to effectively guide federal, IHS, and tribal efforts to reduce and eventually eliminate these disparities. Although health service delivery, financing, and resource allocation are important determinants of health, 27,29 little is known about health service utilization and treatment costs within IHS. Health service utilization and cost findings for US persons with diabetes are not generalizable to American Indians and Alaska Natives with diabetes because of disparities in other indicators of health status, 1–5,8,9,19 access to and use of health services, 1,3–6,30 education, 31,32 and income. 31,32 To address this knowledge gap, we combined for the first time data from 3 different IHS reporting systems—the Resource Patient Management System (RPMS), Contract Health Services, and IHS cost reports—to describe health service utilization and IHS treatment costs for more than 30 000 American Indian adults with and without diabetes. The study population lived in the Phoenix Service Unit, an IHS administrative unit located in central Arizona that includes reservations and rural, suburban, and urban areas. The service unit includes a large regional hospital, the Phoenix Indian Medical Center (PIMC), and several small community-based clinics dispersed throughout the region. Although there is diversity across the IHS in the prevalence of diabetes and health service delivery systems, use of data from this service unit provides an initial opportunity to examine relationships among health status, utilization, and treatment costs.
