Agreement between seven-day and fourteen-day home systolic blood pressure stability scores: A J-HOP study analysis

This study investigated agreement between a score derived from guideline-consistent 7-day home BP monitoring (HBPM) and the score previously derived from 14-day monitoring (which was shown to be associated with cardiovascular prognosis). This was a secondary analysis of the home SBP stability score study using data from the Japan Morning Surge-Home Blood Pressure (J-HOP) study. The home SBP stability score (0-10 points) was calculated based on morning-evening average home SBP, average real variability, average peak home SBP, and time in therapeutic range. Scores were calculated for 14 days (days 1-14), the first week (days 1-7), and the second week (days 8-14). Agreement between scores was evaluated using Spearman's rank correlation coefficients and weighted kappa statistics. Of 4310 J-HOP participants, 3353 were included in this analysis (age 65.0 ± 10.4 years, 45.8% male). Mean home SBP stability scores were similar across the 14-day, first week and second week: 6.2 ± 2.9, 6.2 ± 2.9 and 6.3 ± 2.9 points, respectively. Agreement between the 14-day score and both the first-week (Spearman's correlation coefficient: 0.935 [95% confidence interval (CI) 0.931-0.939]; weighted kappa 0.799 [95% CI 0.790-0.809]) and second-week (Spearman's correlation coefficient 0.894 [95% CI 0.887-0.901]; weighted kappa 0.739 [95% CI 0.728-0.749]) scores was high; agreement between the first-week and second-week scores was lower. These findings support the feasibility of calculating the home SBP stability score from standardized, guideline-recommended 1-week HBPM data in clinical practice. However, week-to-week agreement was moderate, suggesting that short-term classification variability at the individual level should be considered.