How prevalence of hypertension varies as diagnostic criteria change.

In a effort to determine what impact diagnostic criteria might have in defining the magnitude of the "hypertensive" population, various definitions of high blood pressure were applied to the same population. At the initial encounter, 23.3 per cent of the subjects had blood pressures greater than or equal to 160/95 mm Hg, but less than half of these sustained that level on two subsequent occasions over the next three weeks. When an initial diastolic blood pressure of greater than or equal to 105 mm Hg was used to define hypertension, prevalence fell by more than two thirds (23.3 to 7.2 per cent). These results clearly demonstrate that even a very simple modification of diagnostic criteria can markedly alter the prevalence of "hypertension."