A new model for 5-year risk of cardiovascular disease in type 2 diabetes, from the Swedish National Diabetes Register (NDR)

Aim: We assessed the association between risk factors and cardiovascular disease (CVD) in an observational study of type 2 diabetes patients from the Swedish National Diabetes Register.

Methods: A derivation sample of 24,288 patients, aged 30-74 years, 15.3% with previous CVD, baseline 2002, 2488 CVD events when followed for 5 years until 2007. A separate validation data set of 4906 patients, baseline 2003, 522 CVD events when followed for 4 years.

Results: Adjusted hazard ratios at Cox regression for fatal/nonfatal CVD were: onset-age 1.59, diabetes duration 1.55, total-cholesterol-to-HDL-cholesterol ratio 1.20, HbA1c 1.12, systolic BP 1.09, BMI 1.07 (1 SD increase in natural log continuous variables); males 1.41, smoker 1.35, microalbuminuria 1.27, macroalbuminuria 1.53, atrial fibrillation 1.50, previous CVD 1.98 (all p<0.001 except BMI p=0.0018). All 12 variables were used to elaborate an equation for 5-year CVD risk in the derivation dataset: mean 5-year risk 11.9±8.4%. Calibration in the validation dataset was adequate: ratio predicted 4-year risk/observed rate 0.97. Discrimination was sufficient: C statistic 0.72, sensitivity 51% and specificity 78% for top quartile.

Conclusion: This CVD risk model from a large observational study of patients in routine care showed adequate calibration and discrimination, and can be useful for clinical practice.