Prediction of Life-Years Gained Without CVD Events in Diabetes Patients

Study Questions:

Can a risk prediction model developed to assess lifelong cardiovascular disease (CVD) prevention in people with type 2 diabetes mellitus (T2DM) predict life-years gained without myocardial infarction or stroke?

Methods:

The authors developed and validated the DIAL (Diabetes Lifetime-perspective prediction) model, consisting of two complementary competing risk-adjusted Cox proportional hazards functions using data from people with T2DM registered in the Swedish National Diabetes Registry (n = 389,366). Competing outcomes were: 1) CVD events (vascular mortality, myocardial infarction, or stroke), and 2) nonvascular mortality. Predictors were age, sex, smoking, systolic blood pressure, body mass index, hemoglobin A1c, estimated glomerular filtration rate, non–high-density lipoprotein cholesterol, albuminuria, T2DM duration, insulin treatment, and history of CVD. External validation was performed using data from the ADVANCE, ACCORD, ASCOT, and ALLHAT-LLT-trials; the SMART and EPIC-NL cohorts; and the Scottish diabetes register (total n = 197,785).

Results:

Predicted and observed CVD-free survival showed good agreement in all validation sets. C-statistics for prediction of CVD were 0.83 (95% confidence interval, 0.83–0.84) and 0.64–0.65 for internal and external validation, respectively. An interactive calculator is available at www.U-Prevent.com, which combines model predictions with relative treatment effects from trials to predict individual benefit from preventive treatments.

Conclusions:

CVD-free life expectancy and effects of lifelong prevention in terms of CVD-free life-years gained can be estimated for people with T2DM using readily available clinical characteristics. Predictions of individual-level treatment effects facilitate translation of trial results to individual patients.

Perspective:

The prediction tool C-statistic to assess impact of CVD prevention strategies was outstanding for internal validation, but only moderately successful for external validation, which is not usual. The website is interesting and worth a look-see. It gives a perspective of relative value of additional treatment for CVD-free survival, which upon entering a few sample patients, does not improve outcome in relatively lower-risk patients as much as physicians would expect despite awareness of the clinical trials. In contrast, the value in intermediate-risk patients should be very convincing even to the skeptic reluctant patient.

Clinical Topics: Diabetes and Cardiometabolic Disease, Dyslipidemia, Prevention, Lipid Metabolism, Nonstatins, Smoking

Keywords: Albuminuria, Aspirin, Blood Pressure, Body Mass Index, Cholesterol, HDL, Diabetes Mellitus, Type 2, Glomerular Filtration Rate, Glucose, Insulin, Life Expectancy, Lipids, Metabolic Syndrome X, Myocardial Infarction, Primary Prevention, Risk Assessment, Smoking, Stroke, Vascular Diseases


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