Blood pressure cutoffs for white-coat and masked effects in a large population undergoing home blood pressure monitoring

The values used to define the presence of white-coat or masked blood pressure (BP) effects are arbitrary. The aim of this study was to investigate the accuracy of several cutoff points based on the difference between office and home BP (ΔBP) values to detect white-coat uncontrolled (WUCH) and masked uncontrolled (MUCH) hypertension, which are phenotypes with adverse prognoses, in a large cohort of treated hypertensive patients. This multicenter cross-sectional study included 6,049 treated hypertensive patients (40% males, mean age 59.1 ± 14.4 years) who underwent office and home BP monitoring. We compared the sensitivity, specificity, area under curve (AUC), and positive (PPV) and negative (NPV) predictive values of several ΔBP cutoffs to detect WUCH and MUCH. The 15/9 mmHg cutoff, which reflects a 1.0 standard deviation of the ΔBP, showed the best AUC (0.783, 95% CI = 0.772–0.794) for the detection of WUCH, particularly in individuals with office grade 1 hypertension (AUC = 0.811, 95% CI = 0.793–0.829). The −1/−1 mmHg cutoff, which considers all individuals who had lower systolic or diastolic BP levels in the office than at home, had the highest AUC (0.822, 95% CI = 0.808–0.836) for the detection of MUCH. Both cutoff values also had the best performances for identifying all patients with higher and lower office-than-home BP grades. In conclusion, the 15/9 and −1/−1 mmHg cutoffs showed the best performance for the detection of treated hypertensive patients with WUCH and MUCH, respectively, and therefore might be markers of significant white-coat and masked effects and could be useful for identifying preferential targets for more routine home BP measures.