The RDS tests include: large and small artery elasticity (measured by pulse contour analysis), resting blood pressure, mild treadmill exercise test, carotid IMT, left ventricle mass, ECG, retinal vasculature evaluation, as well as quantification of serum NT-proBNP, and microalbuminuria. Quantitative results from these tests are converted into categorical classifications based on values stratified by age and gender when appropriate. The categorical data is scored as follows: normal = 0 points, borderline = 1 point, abnormal = 2 points. Point values from all parameters are summed to create the RDS, with values ranging from 0-20. Scores of 0-2 are classified as normal, 3-5 as early disease, and 6+ as advanced disease. Previous research has shown that the RDS is a powerful predictor of future cardiovascular events.