Asthma, misunderstood and misdiagnosed

25th March, 2007

Asthma, misunderstood and misdiagnosed

Many thousands of New Zealanders are being treated for asthma when in fact another condition may be the cause of their illness. Ground-breaking research is being discussed today at the Thoracic Society of Australia and New Zealand’s Annual Scientific Meeting currently being held in Auckland.

Asthma is the leading respiratory disease diagnosed in New Zealand, Australia, Canada and the United States, with more than 20% of the population diagnosed with the condition.

Three of the world’s leading asthma researchers, Professors Robin Taylor (University of Otago, New Zealand), Peter Gibson (John Hunter Hospital, Australia) and Ian Pavord (University of Leicester, England) have studied and validated a number of new tests which allow a more accurate assessment of the patient to be made. The tests can tell the clinician whether they are under-treating or over-treating the patient or whether in fact the diagnosis of asthma is accurate or not.

Damage to the small breathing tubes during childhood or adolescence when they are more vulnerable to damage may lead to symptoms which may mimic asthma. Making an accurate diagnosis is essential to good management and may save the country millions of dollars in medication costs.

The new tests, which are available only in a few New Zealand hospitals running clinical trials, suggest that a significant proportion of people being treated for asthma because of a chronic cough, wheeze or chest tightness, may in fact have other inflammatory conditions which respond better to other medications.

While the physicians are not suggesting people throw away their inhalers, they are saying that a few specific tests such as expired nitric oxide measurement, sputum analysis and CT scans can differentiate between true asthma and damaged airways. If the lung disease is not true asthma, patients will respond more readily to different medication regimens and will enjoy an improved quality of life.

“The challenge for the Thoracic Society will be to evaluate ways of transferring the results of tests undertaken in the laboratory into the clinical work place” said Dr Jeff Garrett, the local branch president of the Society. “The results of the studies currently being conducted in our leading hospitals in New Zealand will hopefully give us more direction”.

Asthma medications account for around $NZ60 - 80 million of pharmaceutical budget per year. Accurate diagnosis and evaluation of asthma severity could substantially reduce pharmaceutical costs.

For further information, please call Associate Professor Jeff Garrett, President, NZ Branch, Thoracic Society of Australia and New Zealand and the Clinical Director of Medicine, Middlemore Hospital, ph 021 784 097.

ENDS