HOW TO MEASURE BLOOD PRESSURE: Studies conducted in large series have established the prognostic value of blood pressure measured by conventional methods. This measurement technique has however a certain number of limitations and alternative systems have been proposed, including self-monitoring methods. A preliminary study suggested that the prognostic value of self-monitoring blood pressure measurements would be superior to those obtained with conventional methods. These findings require confirmation. A LARGE SCALE STUDY: The primary objective of the SHEAF study is to determine the prognostic value of self-monitoring blood pressure measurements in terms of cardiovascular mortality in a population of hypertensive elderly subjects living in France. The study protocol projects to include 5,000 hypertensive patients, whether treated or not, aged 60 and over. Baseline pressures are to be measured by a physician using a mercury sphygmomanometer (3 successive measurements at 2 visits) and by the participants using a self-monitoring device in their home (3 measurements in the morning and evening for 4 consecutive days). The patients will be followed for 3 years and all cardiovascular events will be recorded, including: death, myocardial infarction, cerebral vascular events, transitory ischemic events, hospitalization for angina, episodes of angina, heart failure, angioplasy or coronary bypass. The results of this large-scale epidemiology study should be available in 2002. METHODOLOGICAL PRECAUTIONS: The SHEAF study will analyze the patient's usual blood pressures, whatever the treatment at study inclusion, rather than blood pressures observed after treatment withdrawal. Efforts will be made to limit the number of drop-outs.