By Kate Kelland
LONDON (Reuters) - Taking repeated blood pressure readings over a 24-hour period rather than a one-off measurement in the clinic is the most cost-effective way of deciding who should be prescribed drugs for hypertension, according to a study published Wednesday.
The findings in favor of so-called ambulatory blood pressure monitoring were immediately adopted by Britain's health costs watchdog, the National Institute for Health and Clinical Excellence (NICE), in new guidelines on how to diagnose and when to treat high blood pressure.
Bryan Williams, a professor of medicine at the Leicester University and chair of the NICE guideline development group, said the change would affect the treatment of millions of people in Britain and was "a step-change that is likely to be replicated across the world."
An estimated 1 billion people around the world have high blood pressure, or hypertension, which is a major risk factor for cardiovascular disease, the leading cause of death globally. If it is left untreated, high blood pressure can cause strokes, heart attacks, heart failure and organ damage, including kidney failure and vision problems.
Those diagnosed with hypertension are often prescribed one of many blood-pressure lowering drugs such as Novartis's Lotensin or generic benazepril, candesartan, sold as Atacand by AstraZeneca and Takeda, or Novartis' Diovan, known generically as valsartan.
Patients are often prescribed the drugs for many years if not the rest of their lives.
"Ambulatory monitoring allows better targeting of blood pressure treatment to those who will receive most benefit," said Richard McManus of Britain's Birmingham University, who led a study published in The Lancet medical journal which prompted the NICE guideline change.
"It is cost saving in the long term as well as more effective, and so will be good for patients and doctors alike."
Diagnosis of hypertension has traditionally been based on blood-pressure measurements in the clinic, but studies have found that home and ambulatory measurements are better indicators of who will suffer heart problems and strokes.
Ambulatory blood pressure measurement involves the patient wearing a blood pressure cuff attached to an automatic blood pressure machine for 24 hours. Measurements are taken typically half hourly during the day and hourly during the night.
Experts say one-off blood pressure readings taken during a visit to the doctors can often be artificially raised due to what is known as the "white coat effect" when patients are nervous about going into a clinical setting.
In the Lancet study McManus' team analyzed the cost-effectiveness of the three approaches and found that ambulatory monitoring was the most cost effective way to diagnose high blood pressure in men and women of all ages.
It saved money in all groups and resulted in significant improvements in quality of life for both sexes in the 50-plus age group.
McManus said the new NICE guidelines marked a significant change in hypertension care. "The use of ambulatory monitoring will ensure quicker and more accurate diagnosis," he said, adding that this was "an exciting advance which I am sure will be taken up internationally."
(Editing by David Cowell)