Fig. 1

Concept of three-index blood pressure variability evaluated using office measurement. The left figure shows the concept of within-individual variability and visit-to-visit BP variability (intraindividual variability). If SD is used as the index of BP variability, within-individual variability is defined as SD using multiple BP measurements at one visit (dotted line box). Visit-to-visit BP variability is defined as SD using multiple measurements on multiple visits (solid line box). In this case, within-individual variability in patient A (10 mmHg) is higher than that in patient B (5 mmHg), and visit-to-visit BP variability in patient B (20 mmHg) is higher than that in patient A (5 mmHg). The right figure shows the concept of interindividual variability. Interindividual variability refers to the SD derived from the calculation of average BP in each group. Interindividual variability on drug B (26 mmHg) is greater than that on drug A (10 mmHg), because BP in patient C did not decrease with intervention using drug Y. BP blood pressure, SD standard deviation