Automated office blood pressure measurement by elderly patients in the waiting room

Abstract

Objective: Unattended automated office blood pressure (AOBP) may be a better estimate of true blood pressure (BP) than conventional office BP by physicians or nurses. However, measurement of AOBP is cumbersome in general clinical practice. We compared unattended AOBP by the patients themselves using the rigid cuff in the waiting room with attended AOBP and home BP (HBP) (N = 72).

Methods: Unattended AOBP by patients was measured in the waiting room using a rigid cuff with the fully automated device (Omron, HEM-907, triple BP readings taken at 1-min intervals after 5 min of rest). Attended AOBP was measured using a soft cuff by a physician in an examination room without specific resting time. HBP was measured for 5 consecutive days.

Results: The mean age was 76.5 ± 8.6 years. The mean systolic unattended AOBP by patients, attended AOBP and HBP were 139.3 ± 16.6, 144.8 ± 17.1 and 139.1 ± 14.4 mmHg, respectively. Unattended AOBP by patients was significantly related to attended AOBP (r = 0.798; P < 0.01) and to HBP (r = 0.404; P < 0.001). It was significantly lower than attended AOBP (difference 5.5 ± 10.7 mmHg; P < 0.001) and comparable with HBP (difference 0.26 ± 17.0 mmHg; P = 0.90) in Bland-Altman plots. However, 22% of patients had a difference of over 20 mmHg between unattended AOBP by patients and HBP. Multivariate regression demonstrated older age (B = -0.73; P = 0.002) to be related to the difference between unattended AOBP by patients and HBP.

Conclusion: The mean unattended AOBP by patients was lower than attended AOBP and comparable with HBP, but older age affected the difference between unattended AOBP by patients and HBP.