Background: Blood pressure is the most ubiquitous diagnostic recording made in the doctor's office, but the measurement is subject to a number of sources of bias, which may lead to over- or underestimation. The current study examined the systematic influence of the way in which the measurements were taken - by the physician, by a nurse, or with the patient sitting alone, using an automated device.
Subjects and methods: Blood pressure was measured in 17 essential hypertensive and 10 white-coat hypertensive individuals. On separate clinic visits, measurements were taken by the attending physician, by a nurse and using an automated device (Arteriosonde 1216).
Results: A repeated-measures ANOVA revealed that, for systolic pressure, there was a significant effect of measurement modality on blood pressure. Physician systolic pressures were on average approximately 10 mmHg higher than those taken by a nurse, nurse pressures being approximately 7 mmHg higher than those recorded using Arteriosonde. The effect on diastolic pressure was similar but smaller, and no nurse-Arteriosonde difference was observed.
Conclusions: We conclude that the routine clinical assessment of blood pressure would be more representative of daily ambulatory pressure if an automated device, without doctor or nurse present, were used.