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.