Devices for blood pressure self measurement: tested in comparison

Comparative clinical evaluation of instruments designed for the self-measurement of blood pressure.

The usefulness of 27 different, exclusively oscillometric, automated devices were tested on a single group of 24 test persons without pressure-reducing arterial stenoses in the upper extremity. The cuff was to be put on the upper arm with 20 devices, on the wrist with five devices and on the left index finger with two devices. Per device and test person, six sequential comparative measurements were carried out using automated self-measurement and standard method with a double stethoscope in the same arm.

On average, the devices measured the systolic pressure between 13.2 mmHg lower and 3.5 mmHg higher than the standard procedure; the diastolic pressure was measured between 17.4 and 0.2 mmHg lower. Using a scoring system, in which a device only got points for a comparative measurement if the differences to the control in systolic and diastolic measurement both were < or = 10 mmHg, the devices gained between 67 and 259 out of a maximum of 576 points. If each of the test persons had opted to buy just those devices which revealed a mean systolic and diastolic error of < or = 5 mmHg in his or her case, younger test persons would have found zero to five suitable devices older persons three to 13. The site of cuff application had no significant influence on results.

Standard measurements and measurements with automated blood pressure self-measurement devices can differ considerably. In young test persons less suitable instruments are found than for older persons.