Most of the current diabetes prediction models heavily relied on the UKPDS risk engine and Framingham equation, which used data from 1970s on European populations. This study aimed to update a risk engine using a cohort of patients with type 2 diabetes in the United States (US). METHODS:

A total of 21 equations for forecasting diabetes-related microvascular and macrovascular events, hypoglycemia, mortality, and progression of diabetes risk factors were estimated using data on 10,251 patients from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial.

Left truncated proportional hazard model or accelerated failure time model was applied to fit each event equation using diabetes duration as time index, and a large variety of distributions including Weibull and Gompertz distribution were tested. 10-folds cross-validation or bootstrapped validation was applied to account for overfitting issue. Predicted cumulative incidence rates was plotted against the observed cumulative incidence to serve as internal validation. RESULTS:

The model’s forecast fell within the 95% confidence interval for the observed events at each time point up to 40 years diabetes duration. Our model prediction provides accurate prediction according to the internal validation process, and good face validity on risk factors were established by endocrinologists. Severe hypoglycemia was found to be an important risk factor for congestive heart failure (CHF), myocardial infarction (MI), angina, revascularization surgery, and diabetes-related mortality. Racial factor was included in more than half of the events equations. CONCLUSIONS:

The updated risk engine for the US diabetes cohort has a good internal validity to simulate events that closely match observed outcomes in the ACCORD trial. With extrapolation over lifetime, a simulation model based on the updated risk engine can also predict a range of long-term outcomes, thus assist making clinical and policy decisions. We are currently conducting external validation of this updated risk engine.