The diagnosis, management, treatment, epidemiology and research of hypertension is dependent on accurate measurement of blood pressure. If blood pressure measurement is inaccurate, it follows that incorrect decisions will be made. All too often the accuracy of measurement is taken for granted or ignored, leading to inaccurate measurement with the result that many people are at risk of being mislabelled as having hypertension and being given unnecessary treatment. With over 20% of the adult population suffering from hypertension the consequences of inaccurate measurement carry serious implications for health care delivery and for society.

Over the last twenty or so years, the accuracy of the conventional technique of blood pressure measurement using a stethoscope and mercury sphygmomanometer has been questioned and efforts have been made to improve the technique with automated devices. In the same period, recognition of the phenomenon of white coat hypertension, whereby some subjects with apparent elevation of blood pressure have normal, or reduced, blood pressures when measurement is repeated away from the medical environment, has focused attention on methods of measurement, which provide profiles of blood pressure behaviour rather than relying on isolated measurements under circumstances that may in themselves influence the level of blood pressure recorded.

Ambulatory blood pressure measurement, known as ABPM, has been developed to provide a profile of blood pressure over 24-hours. ABPM has now become indispensable to good clinical practice and should be available to all patients diagnosed as having hypertension. In recognition of this a number of national societies have published recommendations for the use and interpretation of ABPM in clinical practice, and the European Society of Hypertension has published recommendations on blood pressure measuring devices, including devices for ABPM. Self-measurement of blood pressure is becoming increasingly popular, especially among patients, to provide blood pressure measurements outside the medical environment. Finally, the growing move to ban mercury from the clinical environment has created an enormous market for automated devices. However, only a small number of the many automated blood pressure measuring devices on the market are independently validated for accuracy, and of those that have been validated less than half fulfill the criteria for accuracy.

An accurate device is fundamental, therefore, to all forms of blood pressure measurement, whether in the hospital, home, or over 24 hours. It is acknowledged that the accuracy of blood pressure measuring devices should not be based on claims from manufacturers, which can at times be somewhat extravagant, and independent validation with the results published in peer reviewed journals should be demanded. However, manufacturers often ignore this recommendation and potential purchasers are generally unaware of this requirement, assuming – not unreasonably – that if a product reaches the market place, it will measure blood pressure accurately.

This has serious repercussions for patients who may be placed on life-long drug treatment as a result of inaccurate blood pressure measurement. Inaccurate measurement can also have important and costly implications for people taking out life or health insurance. These issues have serious and far-reaching financial implications for national health care budgets.

It is generally recognised that it is extremely difficult for doctors and others wishing to purchase blood pressure measuring devices to obtain up-to-date information on the validation status and accuracy of these devices. Device manufacturers complain about the long and costly time lag between validation of a device and the subsequent publication, which gives it the credibility in the marketplace. It is hoped that this website will address these needs.