To wait or not to wait 1 min between office blood pressure readings.
OBJECTIVE
It is recommended to wait at least 1 min between blood pressure (BP) readings. However, there is insufficient evidence on the utility of this recommendation using a validated automatic device. The aim was to assess differences in BP according to the waiting time between BP readings.


METHODS
The study was designed as a cross-sectional descriptive study in hypertensive patients attended in primary care.Patients were seated for 5 min before six baseline BP readings: three BP measurements with no waiting time [immediate readings (IR)] between them and three BP measurements with 1 min of waiting time [waiting readings (WR)] between each reading, in random order. The intraclass correlation coefficient was calculated between IR and WR mean BP measurements, with 95% confidence intervals (CIs).


RESULTS
We included 150 hypertensive patients, 49.3% women, 65.6 (12.8) years of age. The mean systolic blood pressure (SBP) values for IR and WR measurements were 137.2 (95% CI 134.2-140.2) and 137.8 (95% CI 134.8-140.8) mmHg, respectively. The mean diastolic blood pressure (DBP) values for IR and WR measurements were 79.4 (95% CI 77.5-81.4) and 79.7 (95% CI 77.7-81.8) mmHg, respectively. Intraclass correlation coefficient between IR and WR was 0.959 (95% CI 0.943-0.970) and 0.926 (95% CI 0.898-0.946) for SBP and DBP, respectively. The mean difference between both methods for SBP and DBP was -0.60 (95% CI -1.79 to 0.5) and -0.27 (95% CI -1.33 to 0.77) mmHg, respectively.


CONCLUSIONS
We found a good agreement between waiting or not waiting 1 min between office BP readings. This demonstrates that both methods of BP measurement appear to be interchangeable.
aLa Mina Primary Care Center, University of Barcelona bBarcelona Research Support Unit, Catalan Health Institute, Barcelona, Spain.
Ernest
E
Vinyoles
Maria
M
Cecilia
Marta
M
García-Alfaro
Mònica
M
Vera
Maria Isabel
MI
Fernández-San Martín
D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D013997:Time Factors