Computer modeling of diabetes and its complications: a report on the Fifth Mount Hood challenge meeting.

OBJECTIVES: The Mount Hood Challenge meetings provide a forum for computer modelers of diabetes to discuss and compare models, to assess predictions against data from clinical trials and other studies, and to identify key future developments in the field. This article reports the proceedings of the Fifth Mount Hood Challenge in 2010. METHODS: Eight modeling groups participated. Each group was given four modeling challenges to perform (in type 2 diabetes): to simulate a trial of a lipid-lowering intervention (The Atorvastatin Study for Prevention of Coronary Heart Disease Endpoints in Non-Insulin-Dependent Diabetes Mellitus [ASPEN]), to simulate a trial of a blood glucose-lowering intervention (Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation [ADVANCE]), to simulate a trial of a blood pressure-lowering intervention (Cardiovascular Risk in Diabetes [ACCORD]), and (optional) to simulate a second trial of blood glucose-lowering therapy (ACCORD). Model outcomes for each challenge were compared with the published findings of the respective trials. RESULTS: The results of the models varied from each other and, in some cases, from the published trial data in important ways. In general, the models performed well in terms of predicting the relative benefit of interventions, but performed less well in terms of quantifying the absolute risk of complications in patients with type 2 diabetes. Methodological challenges were highlighted including matching trial end-point definitions, the importance of assumptions concerning the progression of risk factors over time, and accurately matching the patient characteristics from each trial. CONCLUSIONS: The Fifth Mount Hood Challenge allowed modelers, through systematic comparison and validation exercises, to identify important differences between models, address key methodological challenges, and discuss avenues of research to improve future diabetes models.

Lower visual acuity predicts worse utility values among patients with type 2 diabetes.

OBJECTIVE: We estimated the quality of life impact of vision loss in a community-based population with diabetes. DESIGN AND METHODS: We randomly surveyed 4,000 members of a large health maintenance organization with type 2 diabetes to assess quality of life using the EQ-5D instrument. Visual acuity was obtained by automated text processing of clinical notes recorded during the two years preceding subjects' surveys. Natural language processing was used to collect data from electronic medical records and to read clinical notes to determine the stage of retinopathy. Linear regression was used to model quality of life scores. RESULTS: Of the 4,000 surveys sent, approximately 55% of patients responded. Patients with > or = 20/20 acuity reported the highest mean utility (mean = 0.82), which declined as the visual angle doubled to 20/40 (mean = 0.75), and then doubled again to < or = 20/80 (mean = 0.71). Perfect utility (1.0) was reported by 28% of the sample. Only 7% of patients suffered visual impairment (< or = 20/40), and lower levels of visual acuity rarely occurred. Compared with patients with > or = 20/20 acuity, the first doubling of the visual angle (20/40) lowered utility by three points (95% confidence interval [CI], -0.05 to -0.01), and the second doubling of the visual angle (< or = 20/80) lowered utility by six points (95%CI, -0.10 to -0.02). CONCLUSIONS: This study aimed to estimate disutility associated with visual loss in patients with diabetes using a community-based sample and controlled for many characteristics associated with quality of life. We found a smaller utility decrement compared to other studies, suggesting that visual acuity's impact on the quality of life for patients with diabetes in the community setting differs from more selected populations.