The study examined the following factors that were key elements in the evaluation of screening: 1) within-person variability of BP and lipid measurements (i.e., the reliability of the test) and its impact on tracking of BP and lipids from childhood to adulthood, 2) calculation of predictive values, sensitivity, and specificity of childhood BP and lipid measurements considered as screening tests for adult values, after correcting for within-person variability (i.e., validity), 3) one potentially effective intervention for BP control in children, that is, calcium supplementation, and 4) evaluating the cost-effectiveness of screening to identify children at high risk of developing adult hypertension or hyperlipidemia.