24-hour ambulatory systolic blood pressure

Method

Mean systolic pressure across a 24-hour ambulatory blood pressure monitoring recording, from an automated oscillometric device taking readings at fixed intervals through waking and sleeping hours. Device, sampling interval, and the proportion of valid readings recorded on the edge; a recording with too few valid readings is not this measurement.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

Confused with office systolic blood pressure, a small number of seated readings taken in a clinic. The two differ systematically — ambulatory means run several mmHg lower and are free of the white-coat effect — and an intervention can move one without moving the other, so they are separate nodes and are never pooled. Also distinct from the daytime and night-time ambulatory means and from the ambulatory DIASTOLIC mean, all of which are separate numbers printed on the same report. Mean arterial pressure, co-reported in critical care, is a different derived quantity again.