General practitioners' perception of hypertension.

As part of a study to determine the prevalence of microscopic haematuria in hypertensive patients, 12 doctors were asked to record pre-treatment levels of blood pressure. Analysis of 163 recordings of systolic and 192 recordings of diastolic pressure demonstrated: marked zero preference; point V, the point of disappearance of sounds, as the more commonly used diastolic end point; and marked clustering of diastolic readings at 110 mmHg. The last finding suggests that this reading accompanies the decision to treat.