The Charlottesville Blood-Pressure Survey. Value of repeated blood-pressure measurements.

The population of a community of 29,608 adults was screened door-to-door for elevated blood pressure. Of 12,371 adults screened, 20% were classified as hypertensive. After repeated blood-pressure measurement, however, there were only 9% with sustained hypertension, while 11% had labile hypertension. Sixty percent of the cases of sustained hypertension had been either undiagnosed, untreated, or inadequately treated. Eighty-two percent who initially were unaware of hypertension had labile hypertension after repeated blood-pressure measurement, and 18% were unaware of having, sustained hypertension. Labile hypertension was most prevalent in the young and decreased with age. In contrast, sustained hypertension was least prevalent in the young and increased with age. Labile hypertension was most prevalent in white men, and sustained hypertension was more prevalent in blacks than in whites. Labile hypertension represents a large segment (52%) of the population initially identified as having hypertension in a home blood-pressure survey.