PP.06.05] IS OFFICE BLOOD PRESSURE MEASUREMENT RELIABLE FOR INDIVIDUAL DECISION MAKING – RESULTS OF THE IPARR TRIAL

Abstract

Objective: Standard operating procedures (SOP) for office blood pressure measurement (OBPM) vary highly between different guidelines. Similarly, outcome studies have used different methods to measure office blood pressure. Until today OBPM is used for clinical decision making. We aimed to compare an OBPM procedure based on the one used in the SPRINT study, but attended by an operator, to a single OBPM as used in early outcome studies and many clinical settings. Design and method: In this cross-sectional, single-center trial, 1000 adult subjects were recruited until February 2016. Seven sequential blood pressure measurements were performed after five minutes of rest in a quiet room and in sitting position in the presence of an operator. The initial measurement was taken using a standard device (Omron HBP-1300 professional blood pressure monitor, appropriate cuff size), alternating with a tested smartphone app. Over all, 4 standard and 3 smartphone measurements were taken, however, only the standard measurements were used for this study. The standard OBPM were spaced 2 min apart. Additional information about cardiovascular risk factors, concomitant disease, and medication were collected. We compared the first measurement out of 4 to the mean of last three measurements. Results: Complete measurements were available in 802 subjects. The first measurement had a median of 129 mmHg (IQR 116–140) in comparison to the mean of the last 3 measurements of 123 mmHg (IQR 113–134), which were significantly different (p-value < 0.0005). The Bland-Altman plot showed a high variability between the measurement methods (Figure 1). 662 subjects (82.5%) showed a difference of >2 mmHg, 441 (55.0%) a difference of >5 mmHg and 208 (25.9%) of >10 mmHg between the methods. Both a decrease and increase of the values were observed and could not be predicted clinically.Conclusions: There are significant differences in the results of two different SOP leading to a discrepancy of more than 5 mmHg in more than half of the patients in one measurement session. This difference could not be predicted by clinical parameters obtained in the trial. Therefore OBPM seems to be unreliable for individual clinical decision making until there are proper SOP.