Blood pressure self-measurement in normotensive and hypertensive patients.

In this study casual blood pressure was compared with home blood pressure measurement in 41 normotensive, 39 hypertensive and 21 borderline hypertensive subjects. The average casual readings for the whole group were 8.6 mmHg higher for systolic and 4.0 mmHg higher for diastolic pressures than self-determined values. Casual and home-registered blood pressures showed a highly significant relationship (P less than 0.001) for both systolic and diastolic blood pressure readings. In the distribution of self-measured diastolic blood pressure readings, normotensive subjects rarely (5%) showed values higher than 90 mmHg, whereas hypertensive subjects had a relatively high percentage of diastolic readings above that level (55%). The results confirm previous reports of lower self-determined than casual blood pressure values. However, the high correlation between these two methods of blood pressure measurement indicates that in general there is a quantitative rather than a qualitative difference between casual and self-registered blood pressures. Finally, self-registered diastolic values exceeding 90 mmHg may be interpreted as hypertensive.