Use of Different Blood Pressure Thresholds to Reduce the Number of Home Blood Pressure Monitoring Days Needed for Detecting Hypertension

Abstract

BACKGROUND: Home blood pressure (BP) monitoring over a 7-day period is recommended to confirm the diagnosis of hypertension. METHODS: We determined upper and lower home BP thresholds with >90% positive predictive value and >90% negative predictive value using 1 to 6 days of monitoring to identify high home BP (systolic BP ≥130 mm Hg or diastolic BP ≥80 mm Hg) based on 7 days of home BP monitoring. The sample included 361 adults from the Improving the Detection of Hypertension Study who were not taking antihypertensive medication. We used two 7-day periods, at least 3 days apart, the first being a sampling period and the second a reference period. For each number of days in the sampling period, we determined the percentage of participants who had a high likelihood of having (>90% positive predictive value) or not having (>90% negative predictive value) high BP and would not need to continue home BP monitoring. Only the participants in an uncertain category (ie, positive predictive value ≤90% and negative predictive value ≤90%) after each day were carried forward to the next day of home BP monitoring. RESULTS: Of the 361 participants (mean [SD] age of 41.3 [13.2] years; 60.4% women), 38.0% had high home BP during the reference period. There were 63.7%, 17.1%, 10.5%, 3.3%, 3.6%, and 1.4% participants who would not need to continue after 1, 2, 3, 4, 5, and 6 days of monitoring. CONCLUSIONS: In most people, high home BP can be identified or excluded with a high degree of confidence with 3 days or less of monitoring.