Awareness, treatment and control of hypertension: the 'rule of halves' in an era of risk-based treatment of hypertension.

Detection, treatment and control of high blood pressure in many populations are insufficient. We reported current prevalence, awareness, treatment and control of hypertension in the Netherlands and compared the findings with other studies. Furthermore, we related actual treatment of hypertension to estimated absolute 10-year cardiovascular risk, as according to current guidelines on this subject, initiation of blood pressure-lowering treatment depends on the level of cardiovascular risk. The Utrecht Health Project is a prospective cohort study in a suburb of Utrecht. Information on medical history, life style and measurements of blood pressure, cholesterol and glucose of the first 4950 participants of the study was obtained. Cardiovascular risks were calculated using the Framingham risk function. Prevalence of hypertension was 23.3%. Among those with hypertension, 33.7% was aware of the condition. Of those aware, 59.4% was treated. Of those treated, 41.9% had blood pressure below the recommended level. In half of those aware of their hypertension, and a calculated cardiovascular risk less than 10%, treatment of hypertension was started unnecessary. Of those aware of their hypertension with a calculated cardiovascular 10 years risk exceeding the treatment threshold of 20%, treatment was absent in 33.6%. Awareness and control of hypertension are still inadequate in the Netherlands and comparable with other European countries. Management of hypertension is too often not risk-based despite recommendations in guidelines on prevention of cardiovascular diseases available since 2000.