The best protocol for home blood pressure monitoring (HBPM) is not well defined. In this study, we compare two protocols of HBPM considering 24 h ambulatory blood pressure monitoring (ABPM) as a reference standard for the diagnosis of hypertension.Methods
One hundred and fifty-eight patients were subjected to 24 h ABPM and to a 3-day (33 measurements) and a 5-day (27 measurements) HBPM protocol. Single-void urinary albumin concentration and echocardiographically determined left ventricular mass were also assessed. Hypertension was defined as blood pressure more than 135/85 mmHg for HBPM and more than 130/80 mmHg for ABPM.Results
Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios were higher for the 3-day HBPM protocol than the 5-day protocol. The area under the ROC curve (95% confidence interval) was 0.82 (0.75–0.90) for the 3-day protocol and 0.69 (0.60–0.78) for the 5-day protocol. Bland–Altman plots showed smaller dispersion for the 3-day protocol. The values of κ statistics were better with the 3-day HBPM. There was a better association between the 3-day protocol and urinary albumin concentration and left ventricular hypertrophy.Conclusion
A 3-day protocol of HBPM has better accuracy than a 5-day protocol for the diagnosis of hypertension considering ABPM as a reference standard.