SHORT-TERM VARIATION IN BLOOD-PRESSURE DETERMINES THE ACCURACY OF SIMULTANEOUS AND SEQUENTIAL RECORDINGS IN THE VALIDATION OF BLOOD-PRESSURE MEASURING DEVICES

Short-term intradevice variation of BP was determined by means of consecutive BP recordings. The intradevice variation was mainly the result of spontaneous, random variation in BP and was the same for invasive, automated oscillometric and auscultatory random zero meter recordings. We show that the accuracy of simultaneous and sequential recording's, performed according to the recommendation of the British Hypertension Society's protocol for the evaluation of automated BP devices, can be calculated by means of statistical analysis if the intradevice variation of the BP is known. We found, for both sequential and for simultaneous recordings, a close agreement between the expected and the observed proportion of differences that fall within certain specified limits and that it is more favourable for a test device to be evaluated by sequential than by simultaneous recordings.