Experts raise concern over unnecessary treatment of mild hypertension in low risk people

Lowering the drug threshold for high blood pressure has exposed millions of low-risk people around the world to drug treatment of uncertain benefit at huge cost to health systems, warn US experts in BMJ today.

Dr Stephen Martin and colleagues argue that this strategy is failing patients and wasting healthcare resources. They call for a re-examination of the threshold and urge clinicians to be cautious about treating low risk patients with blood pressure lowering drugs.

Their paper publishes as the Preventing Overdiagnosis conference opens next week (Monday 15 Sept), where experts from around the world will discuss how to tackle the threat to health and the waste of money caused by unnecessary care. The conference is hosted by the Centre for Evidence-Based Medicine at the University of Oxford in partnership with The BMJ's Too Much Medicine campaign.

Up to 40% of adults worldwide have hypertension, over half of which is classified as "mild." Low risk indicates that an individual does not have existing cardiovascular disease, diabetes, or kidney disease.

Over the years, hypertension has been treated with drugs at progressively lower blood pressures. The belief has been that drug treatment of even mildly elevated blood pressure levels in low risk patients may reduce cardiovascular risk.

Over half of people with mild hypertension are treated with medication. Yet treating low risk mildly hypertensive patients with drugs has not been proven to reduce cardiovascular disease or death.

In the US alone, where hypertension is the most common condition for a medical visit, the cost of drug treatment of mild hypertension has been estimated at $32 billion (£19bn; €24bn) per year. This corresponds to more than 1% of annual healthcare costs and more than one third of total US expenditures on public health.

The authors argue that overemphasis on drug treatment "risks adverse effects, such as increased risk of falls, and misses opportunities to modify individual lifestyle choices and tackle lifestyle factors at a public health level."

And they urge clinicians to share the uncertainty surrounding drug treatment of mild hypertension with patients, measure blood pressure at home, improve accuracy of clinic measurements, promote public health investment, and "encourage lifestyle changes to treat hypertension, including weight loss, smoking cessation, decreased alcohol consumption and increased exercise."

An animation to illustrate mild hypertension and its management is available here.