University Medical Centre Utrecht examined the medical records of 652 children in the Netherlands who had been diagnosed with asthma and found that 53.5 percent of them had signs and symptoms that "made asthma unlikely," leading to the conclusion that they "were most likely over-diagnosed."
The report, which was published by the peer-reviewed British Journal of General Practice, has triggered concern in the U.K. because the Netherlands consistently tops polls of the best healthcare in the Europe, meaning the problem could be even worse for British children.
It's believed that over-diagnosis occurs because GPs do not always perform the correct tests for confirming asthma in a child, basing diagnosis on a case history of breathing problems, wheezing and coughing rather than any clinical tests.
The most effective test for asthma is spirometry — which uses a machine to measure how much and how fast a person breathes out. However the Dutch researchers found that this test had only been used in around 16 percent of the cases checked.
In January 2015 the National Institute of Clinical Excellence warned that around one third of adults diagnosed with asthma show no clinical signs of the condition and could be at risk from the side effects of asthma drugs.
NICE is currently using the Dutch report to draw up new guidelines advising doctors to use more clinical tests to back up their judgement and avoid the dangers of wrongly diagnosing someone as asthmatic. The guidance is expected to be published later this year.
Dr. Maureen Baker, Chair of the Royal College of GPs, responded to the report.
"Asthma is an extremely distressing condition affecting one in 11 children, and GPs are highly trained to identify symptoms, prescribe appropriately and monitor treatment to help patients of all ages manage their condition," she said.
"There is, however, no single test that can definitively diagnose asthma, and this can make it difficult to do in primary care, particularly when some common symptoms are similar to those of other illnesses.
"Some useful diagnostic tests are already available in primary care in the U.K., but we need increased investment so that we can broaden GP access to this equipment and undergo the training necessary to use it in the best interests of our patients."
Asthma is a "common long-term condition that can cause coughing, wheezing, chest tightness and breathlessness", says NHS Choices.
One in every 11 children in the U.K. is diagnosed with asthma, which is caused by inflammation of the small tubes, called bronchi, which carry air in and out of the lungs.
When asthma sufferers come into contact with something that irritates the lungs the airways become narrow, the muscles around them tighten, and there is an increase in the production of sticky mucus (phlegm). Common asthma triggers include house dust mites, animal fur, pollen, cigarette smoke, exercise and viral infections.
Although there is no cure for asthma, a number of treatments can help to control the condition, including inhalers, spacers, breathing exercises and steroid tablets.
For more information visit Asthma UK.