Ooh matron, the doctor's white coat is making my blood pressure rocket

PATIENTS with high blood pressure see their levels soar when measured by a doctor rather than a nurse due to a so-called "white coat" effect, according to a landmark study.

High blood pressure affects about 40 per cent of adults in the UK and is a major risk factor for heart attack, heart failure, kidney disease and stroke.

It was already known that some patients can suffer from what is known as the "white coat" effect – seeing their blood pressure levels increase due to nerves or stress when they are being checked by a doctor in a clinical setting.

But a new study by an Aberdeen University-based researcher has revealed that the impact is even more dramatic on patients who are already suffering from very high blood pressure.

The study has shown that their blood pressure levels can rise by as much as 29 units when a doctor checks it, compared with a rise of 17 units if a nurse is taking the measurement.

The findings, published in the latest edition of the British Medical Journal, were based on a major study involving 8,575 patients in Australia.

And the research team is hoping its findings will help shape future guidelines for the diagnosis and treatment of patients suffering from hypertension.

Professor Arduino Mangoni, who recently joined Aberdeen University from Flinders University in Adelaide where the study was conducted, said the study had highlighted the need to encourage greater use of ambulatory blood pressure monitoring where a patient wears a cuff on their arm at home or work which records blood pressure levels at regular intervals over a 24-hour period.

He said: "High blood pressure is a contributory factor in cardiovascular diseases which account for 30 per cent of all deaths, and four million bed days each year, which is 8 per cent of the total health capacity of the NHS.

"Yet current guidelines for the diagnosis and treatment of hypertension don't pay enough attention to the role of ambulatory monitoring, often adopting a one-size-fits-all approach which doesn't properly address different patient groups.

"Our new study will influence hypertension management guidelines worldwide as they take into account varying degrees of hypertension, as well as treatment targets for patients of different genders, ages and with other existing conditions.

"We also hope they will encourage a wider use of ambulatory blood pressure monitoring by clinicians."

Prof Mangoni added: "Hypertension is a chronic disease which often has no symptoms until maybe the patient suffers a stroke.

"It has an enormous health burden. In 2001, the NHS funded 90 million prescriptions for drugs that lower blood pressure at a cost of 840m – nearly 15 per cent of the total annual cost of all primary care drugs.

"Hypertension can also be a tricky condition for clinicians to diagnose and as a result may often be inadequately treated."

A spokeswoman for the research team explained: "The study shows that the higher the patient's blood pressure, the bigger the difference between ambulatory monitoring and what is recorded by a nurse or doctor.

"The difference is particularly high when the blood pressure is measured by a doctor. The differences also vary depending on the sex and age of the patient.

"However, the study also found that the closer the patient's blood pressure to normal levels, the less of a difference between measurements taken by ambulatory monitoring and those taken by a nurse or doctor."