The prevalence of hypertension in the Indian population of Roodepoort (Transvaal).

In a house-to-house study of 318 Roodepoort Indians the prevalence of hypertension was 19% by 1962 World Health Organization criteria and 12% by 1978 WHO criteria. This change in criteria may lead to misinterpretation of trends in the prevalence of hypertension. The mean systolic and diastolic pressures rose with age. Sixty-three per cent of subjects found to be hypertensive were already on therapy and 26% of the hypertensives were undiagnosed until this survey. The proportion of undiagnosed cases has important health implications.