Development and validation, of the economic assessment of glycemic control and long-term effects of diabetes (EAGLE) model

Background: The Economic Assessment of Glycemic control and Long-term Effects of diabetes (EAGLE) model was developed to provide a flexible and comprehensive tool for the simulation of the long-term effects of diabetes treatment and related costs in type I and type 2 diabetes. Methods: EAGLE simulations are based on risk equations, which were developed using published data from several large studies including the Diabetes Control and Complications Trial, the United Kingdom Prospective Diabetes Study, and the Wisconsin Epidemiological Study of Diabetic Retinopathy. Risk equations for the probability of complications (including hypoglycemia, retinopathy, macular edema, end-stage renal disease, neuropathy, diabetic foot syndrome, myocardial infarction, and stroke) were based on regression analyses, using linear, exponential, and quadratic regression formulae. Subsequent cost calculations are made from the simulated event rates. Internal validation of the EAGLE model was completed by comparing simulated event rates with the published event rates used as the basis for the model. Results: EAGLE provides microsimulations of virtual patient cohorts for type 1 and type 2 diabetes over n years in 1-year cycles. Complications include microvascular and macrovascular events and death, which are calculated over time as cumulative incidences. Glycosylated hemoglobin levels over time are simulated in relation to treatment regimen. Internal Validation demonstrated that each mean event rate simulated by EAGLE overlapped with the published mean event (within a range of +/- 10%). Conclusions: The EAGLE model is an evidence-based, internally valid tool for the assessment of the long-term effects of diabetes treatment and related costs.