Event Rates, Hospital Utilization, and Costs Associated with Major Complications of Diabetes: A Multicountry Comparative Analysis

Philip Clarke and colleagues examined patient-level data for over 11,000 participants with type 2 diabetes from 20 countries and find that major complications of diabetes significantly increased hospital use and costs across settings.Background: Diabetes imposes a substantial burden globally in terms of premature mortality, morbidity, and health care costs. Estimates of economic outcomes associated with diabetes are essential inputs to policy analyses aimed at prevention and treatment of diabetes. Our objective was to estimate and compare event rates, hospital utilization, and costs associated with major diabetes-related complications in high-, middle-, and low-income countries. Methods and Findings: Incidence and history of diabetes-related complications, hospital admissions, and length of stay were recorded in 11,140 patients with type 2 diabetes participating in the Action in Diabetes and Vascular Disease (ADVANCE) study (mean age at entry 66 y). The probability of hospital utilization and number of days in hospital for major events associated with coronary disease, cerebrovascular disease, congestive heart failure, peripheral vascular disease, and nephropathy were estimated for three regions (Asia, Eastern Europe, and Established Market Economies) using multiple regression analysis. The resulting estimates of days spent in hospital were multiplied by regional estimates of the costs per hospital bed-day from the World Health Organization to compute annual acute and long-term costs associated with the different types of complications. To assist, comparability, costs are reported in international dollars (Int$), which represent a hypothetical currency that allows for the same quantities of goods or services to be purchased regardless of country, standardized on purchasing power in the United States. A cost calculator accompanying this paper enables the estimation of costs for individual countries and translation of these costs into local currency units. The probability of attending a hospital following an event was highest for heart failure (93%–96% across regions) and lowest for nephropathy (15%–26%). The average numbers of days in hospital given at least one admission were greatest for stroke (17–32 d across region) and heart failure (16–31 d) and lowest for nephropathy (12–23 d). Considering regional differences, probabilities of hospitalization were lowest in Asia and highest in Established Market Economies; on the other hand, lengths of stay were highest in Asia and lowest in Established Market Economies. Overall estimated annual hospital costs for patients with none of the specified events or event histories ranged from Int$76 in Asia to Int$296 in Established Market Economies. All complications included in this analysis led to significant increases in hospital costs; coronary events, cerebrovascular events, and heart failure were the most costly, at more than Int$1,800, Int$3,000, and Int$4,000 in Asia, Eastern Europe, and Established Market Economies, respectively. Conclusions: Major complications of diabetes significantly increase hospital use and costs across various settings and are likely to impose a high economic burden on health care systems. : Please see later in the article for the Editors' Summary Background: Worldwide, nearly 250 million people have diabetes, and this number is increasing rapidly. Diabetes is characterized by dangerous amounts of sugar (glucose) in the blood. Blood sugar levels are normally controlled by insulin, a hormone produced by the pancreas. Blood sugar control fails in people with diabetes because they make no insulin (type 1 diabetes) or, more commonly, because the fat and muscle cells that usually respond to insulin by removing excess sugar from the blood have become insulin insensitive (type 2 diabetes). Type 2 diabetes can be prevented and controlled by eating a healthy diet and exercising regularly. It can also be treated with drugs that help the pancreas make more insulin or that increase insulin sensitivity. Major long-term complications of diabetes include kidney failure and an increased risk of cardiovascular problems such as heart attacks, heart failure, stroke, and problems with the blood vessels in the arms and legs. Because of these complications, the life expectancy of people with diabetes is about ten years shorter than that of people without diabetes. Why Was This Study Done?: Diabetes imposes considerable demands on health care systems but little is known about the direct medical costs associated with treating this chronic disease in low- and middle-income countries where more than three-quarters of affected people live. In particular, although estimates have been made of the overall resources devoted to the treatment of diabetes, very little is known about how the different long-term complications of diabetes contribute to health care costs in different countries. Public-health experts and governments need this information to help them design effective and sustainable policies for the prevention and treatment of diabetes. In this study, the researchers estimate the resource use associated with diabetes-related complications in three economic regions using information collected in the Action in Diabetes and Vascular Disease (ADVANCE) study. This multinational clinical trial is investigating how drugs that control blood pressure and blood sugar levels affect the long-term complications of diabetes. What Did the Researchers Do and Find?: The researchers recorded diabetes-related complications, hospital admissions for these complications, and length of hospital stays in 11,140 patients with severe diabetes from 20 countries who participated in the ADVANCE study. They used “multiple regression analysis” to estimate the number of days spent in hospital for diabetes-related complications in Asia, Eastern Europe, and the Established Market Economies (Canada, Australia, New Zealand, and several Western European countries). Finally, they calculated the economic costs of each complication using regional estimates of the costs per bed-day from the World Health Organization's CHOICE project (CHOosing Interventions that are Cost Effective). Nearly everyone in the study who developed heart failure attended a hospital, but only 15%–26% of people attended a hospital for kidney problems. The chances of hospitalization for any complication were lowest in Asia and highest in the Established Market Economies; conversely, lengths of stay were longest in Asia and shortest in the Established Market Economies. Finally, the estimated annual hospital costs for patients who had a coronary event, stroke, or heart failure were more than Int$1,800, Int$3,000, and Int$4,000 in Asia, Eastern Europe, and the Established Market Economies, respectively (the international dollar, Int$, is a hypothetical currency that has the same purchasing power in all countries), compared to Int$76, Int$156, and Int$296 for patients who experienced none of these events. What Do These Findings Mean?: Because the ADVANCE trial had strict entry criteria, the findings of this study may not be generalizable to the broader population of people with diabetes. Nevertheless, given the lack of information about the costs associated with diabetes-related complications in low- and middle-income countries, these findings provide important new information about the patterns of hospital resource use and costs in these countries. Specifically, these findings show that the major complications of diabetes greatly increase hospital use and costs in all three economic regions considered and impose a high economic burden on health care systems that is likely to increase as the diabetes epidemic develops. Importantly, these findings should help policy makers anticipate the future health care costs associated with diabetes and should help them evaluate which therapies aimed at preventing diabetes-related complications will reduce these costs most effectively. Additional Information: Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000236.