As many as 30 per cent may have been misdiagnosed with asthma / Getty Images


More than one million people who are being treated for asthma may have been misdiagnosed, according to a health watchdog.

Studies show that up to 30 percent of the 4.1 million people who are being treated for asthma in the UK did not show any “clear evidence” of the incurable condition, and may be receiving unnecessary treatment, according to the National Institute for Health and Care Excellence (NICE).

To improve the accuracy of diagnoses, the watchdog has drafted its first guidance on asthma for doctors in England, which includes an array of tests.

Professor Mark Baker, director of clinical practice at Nice, said that there was a "significant problem" with diagnosing  the chronic condition which can cause life-threatening asthma attacks.

“With appropriate treatment and thoughtful monitoring, most people will be able to successfully control their symptoms and be spared from serious harm.

"Accurate diagnosis of asthma has been a significant problem which means that people may be wrongly diagnosed or cases might be missed in others. Our aim with this guideline is to give clarity and set out the most clinical and cost effective ways to diagnose and monitor asthma based on the best available evidence," he said.

"This new draft guideline provides advice for primary, secondary and community care healthcare professionals on the most suitable tests for accurately diagnosing asthma and how to help people monitor and control their symptoms. We now want to hear from all those who provide care for people with asthma in the NHS to ensure all relevant views are considered for the final guideline.”

Asthma is one of the world's most common chronic diseases in childhood, affecting 1.1m children and 4.3m adults in the UK.

Around 10 per cent of the 5.4 million people in the UK with asthma have the most severe form, which leaves them unable to control their symptoms, resulting in frequent attacks, despite taking multiple high-strength medicines.

Nice also said that while there was no “gold standard test” available, with patients diagnosed based on a medical history, it recommended spirometry - a measure of airflow obstruction - as the primary method for children over five and adults over 16.

For children under five, doctors should monitor nitric oxide levels until they are old enough for clinical tests.

Responding to the reports, Asthma UK urged patients to take an annual asthma review, or more frequently for those with severe symptoms, and advised those with the condition to keep a diary and get their technique checked.