Home blood pressure recording in mild hypertension: value of distinguishing sustained from clinic hypertension and effect on diagnosis and treatment. Bath Health District Hypertension Study Group.

To identify the prevalence and magnitude of clinic changes in blood pressure and determine their effects on the diagnosis and treatment of hypertension, 268 patients with a BP greater than or equal to 160/95 mmHg on three consecutive occasions (twice in the general practitioner's surgery and once in the hospital clinic) recorded a home BP series with an electronic sphygmomanometer. Of these patients, 114 had never received antihypertensive treatment and 154 were receiving treatment. On return to the hospital clinic (second clinic visit) the BP was measured independently by the patient and doctor using electronic and mercury sphygmomanometers respectively and compared with the mean BP of the home series. In some 80% of both untreated and treated patients the second clinic BP was higher than the mean BP of the home series and in some 40% of patients a clinic rise of greater than 20/10 mmHg was recorded. Clinic falls in BP occurred in some 20% of both untreated and treated patients, but averaged only 4/4 mmHg. Treatment decisions based on a mean diastolic blood pressure of greater than or equal to 95 mmHg in the home series resulted in antihypertensive treatment not being started in 38% of untreated patients and not increased in 31% or reduced in 16% of treated patients when treatment would have been started, increased or continued unchanged on the basis of the second clinic (fourth recorded) diastolic blood pressure of greater than or equal to 95 mmHg. A patient recorded home series provides a representative sample of BP which distinguishes patients with sustained hypertension from those with clinic hypertension and may help reduce the overdiagnosis and overtreatment of mild hypertension.