Direct comparison of repeated same-day self and ambulatory blood pressure monitoring

The relative roles of self and ambulatory blood pressure monitoring (self BPM, ABPM, respectively) have yet to be clearly defined despite accumulating evidence of self BPM benefits, particularly in hypertension management. In particular, measurements comparable to ABPM have been documented with self-measurement, usually twice daily over one or more days. Nevertheless, ABPM offers a series of recordings performed throughout the day that can be invaluable during drug treatment. Consequently, this study evaluated 18 normotensive and 79 hypertensive patients, including 21 not taking hypotensive agents, and measured their blood pressure at least every 2 h while they were also undergoing ABPM.

Self-measurement was performed between five and 12 times during the day with 77% of subjects preferring self BPM rather than daytime ABPM. When compared with the closest ABP measurement, mean systolic and diastolic pressures were not significantly different throughout the day in both normotensive and hypertensive patients. However, a comparison of a series of ABPM hourly averages (three readings performed closest to the respective self BPM reading) throughout the day in all hypertensive subjects found ABPM readings to be slightly but significantly lower (3.3 systolic, 2.2 mmHg diastolic; P < 0.05).

It is concluded that multiple self-measurements throughout the day provides comparable information to daytime ABPM, is preferred by most patients, and should be a cost-effective alternative in the diagnosis and management of hypertension.