LAUSR

Objective: Automated office blood pressure (AOBP) is a better estimate of true blood pressure (BP) than clinic BP by physicians; however, measurement is complicated and requires some assistance by medical staffs especially for elderly patients. Video instruction explaining how to measure AOBP would be helpful to guide patients to measure AOBP by themselves. Design and method: We enrolled 75 hypertensive patients. AOBP was measured 3 times with one minute interval after 5 minutes of rest by automated BP device (A&D UM-212BLE) with assistance of instructional video. Instructional video was designed originally to describe the way to attach the cuff, press the button, and stay quiet and measure BP in appropriate position. Clinic BP by physician was measured 3 times using the same device. The sequence of AOBP and clinic BP was andomised. Perceived stress when measuring AOBP and clinic BP were evaluated by visual scale analogue. Home BP was taken 5 consecutive days using A&D UA-651BLE Plus. Results: Mean age was 74.5 ± 10.6 (57% men), and 96% of the patients were taking antihypertensive drugs. Mean AOBP, clinic BP, home BP were 135.2 ± 17.2/81.3 ± 11.1, 139.3 ± 16.3/78.6 ± 10.9, 129.2 ± 16.7/72.7 ± 8.9 mmHg respectively. Mean systolic AOBP was significantly lower than clinic BP (4.1 ± 12.2, p = 0.005), and significantly higher than home BP (6.1 ± 17.5, p = 0.004). Mean diastolic AOBP was significantly higher than clinic BP (-2.7 ± 6.0, p < 0.001), and significantly higher than home BP (8.6 ± 8.8, p < 0.001). Difference between AOBP and home BP was associated with magnitude of mental stress when measuring AOBP (r = 0.289, p = 0.013). In a multivariate analysis, mental stress when measuring AOBP was a predictor of difference between AOBP and home BP after adjusting for age, sex, body mass index, and average of home BP (p < 0.001). AOBP and clinic BP were higher among patients who felt stressed when measuring AOBP (r = 0.386, p < 0.001 for AOBP, r = 0.308, p = 0.008 for clinic BP). Conclusions: AOBP measured with assistance of instructional video were significantly lower than clinic BP and higher than home BP, and the differences were determined by magnitude of mental stress associated with AOBP and clinic BP measurement.