PS 05-05 Automated compared to manual office blood pressure and to home blood pressure in hypertensive patients

Abstract

Objective: Automated office blood pressure (BP) was measured in the recently published SPRINT trial; low target values were shown beneficial. We studied the relationships of automated blood pressure, measured in the health care centre, to manual office BP and to home BP. Design and Method: Stable outpatients treated for hypertension were measured automatically, being seated alone in a quiet room, six times after a five-minute rest with the BpTRU device, and immediately afterwards using auscultatory method. Home BP was measured in a subgroup during seven days preceding the visit. Results: The automated, office and home BP values were 131.2 ± 21.8/77.8 ± 12.1, 146.9 ± 20.8/85.8 ± 12.4, and 137.7 ± 17.7/79.4 ± 8.2 mmHg, respectively. Limits of agreement between office and automated BP (2 SDs in the Bland Altman plot) were +42.6 to -12.6/+22.6 to -6.6 mmHg for systolic/diastolic BP; for home and automated BP, they were +45.8 to -25.8/+20.8 to -12.6 mmHg. For patients with two visits, intraclass correlation coefficients of BP values measured during the first and second visit were 0.66/0.72 for systolic/diastolic automated BP and 0.68/0.74 for systolic/diastolic office BP. Conclusions: Automated BP was much lower than manual office BP and still lower than home BP. It showed similar inter-visit variability as office BP. Whether automated BP and “white coat effect”, calculated as office BP – automated BP difference, should be used in clinical practice, deserves further studies.