Blood pressure should be measured at home, watchdog says

Avoids 'white coat effect'

Patients with high blood pressure should have it monitored at home over 24 hours, the UK's health watchdog said.

This is in lieu of visiting a clinic, where measurements can be distorted by the 'white coat effect' - where the patient experiences an increase in blood pressure while it is being measured by their doctor. It is thought that up to a quarter of patients experience white coat effect. This means that patients who have normal blood pressure on a day to day basis may be misdiagnosed by their doctor.

In its new guidelines, the National Institute for Health and Clinical Excellence said patients whose clinic blood pressure is 140/90 mmHg or higher should wear an ambulatory blood pressure monitoring (ABPM) device at home. The monitor straps around the waist and records several blood pressure measurements over 24 hours.

The recommendations are based on substantial new evidence, including a paper published in the medical journal Lancet, which suggest that 24 hour home monitoring is a more accurate and cost effective way of diagnosing hypertension than both clinic and home monitoring.

Bryan Williams, Professor of Medicine at the University of Leicester and Chair of the Guideline Development Group, said: “The important recommendations in this guideline will affect the treatment of millions of people in our country and change the way blood pressure is diagnosed for the first time in more than a century. “Blood pressure is highly variable so we never use a single reading. Patients are asked to come in and see their GP on at least 2 further occasions. But with AMBP, BP is monitoring throughout the day and then an average value is taken.

“This is done away from the doctor's office, so it is a more natural environment and the results are available after a single day.” Professor Williams stressed that AMBP should only be used for making new diagnoses of hypertension. He added that the introduction of ABPM would helping save the NHS £10million after 5 years, by reducing the number of unnecessary consultations and treatment.

Professor Mark Caulfield, President of the British Hypertension Society and a member of the Guideline Development Group, added: “The cost of treating people with hypertension is now cheaper than doing nothing. If left untreated, hypertension will go on to be a greater cost to the NHS through strokes and heart attacks"

The Family GP