Concordance between SD of SBP from 3 to 20 SBP measurements
| Number of BP measurement | Mean SD of SBP, mm Hg | Delta, mm Hg | r | ICC (95% CI) | P value | Number of patients |
| 20 | 13.4±3.7 | Ref | Ref | Ref | Ref | 1344 |
| 16 | 13.3±4.0 | 0.1 | 0.94 | 0.97 (0.96 to 0.97) | <0.001 | 1381 |
| 12 | 13.1±4.2 | 0.3 | 0.82 | 0.90 (0.89 to 0.91) | <0.001 | 1396 |
| 10 | 12.9±4.4 | 0.5 | 0.77 | 0.87 (0.85 to 0.88) | <0.001 | 1399 |
| 9 | 12.9±4.5 | 0.5 | 0.74 | 0.84 (0.82 to 0.86) | <0.001 | 1401 |
| 8 | 12.8±4.7 | 0.6 | 0.71 | 0.82 (0.80 to 0.84) | <0.001 | 1403 |
| 7 | 12.7±4.9 | 0.7 | 0.66 | 0.78 (0.76 to 0.80) | <0.001 | 1403 |
| 6 | 12.6±5.2 | 0.8 | 0.62 | 0.74 (0.71 to 0.77) | <0.001 | 1403 |
| 5 | 12.6±5.6 | 0.8 | 0.56 | 0.68 (0.65 to 0.72) | <0.001 | 1403 |
| 4 | 12.2±6.0 | 1.2 | 0.47 | 0.60 (0.55 to 0.64) | <0.001 | 1403 |
| 3 | 11.5±6.9 | 1.9 | 0.34 | 0.45 (0.39 to 0.51) | <0.001 | 1403 |
Delta, difference in SD of SBP compared with SD of SBP calculated from 20 BP measurements; ICC, intraclass correlation coefficient; r, Pearson’s coefficient; SBP, systolic blood pressure.