An asthma specialist says an easier test to identify asthma should be more widely used.
New Zealand has the second highest prevalence of asthma in the world, with one in six adults experiencing symptoms.
However Middlemore Hospital's Jeff Garret said many people were misdiagnosed with asthma and given inhalers, when the cause of their breathing difficulty was a bacterial infection in the throat.
He said research published in 2011 showed a cheap and easy blood test could give a proper diagnosis, and it should be used by GPs.
"Sometimes from the research laboratory to the implementation of strategies takes four, five, six years.
"So I'm coming along and saying let's get on with this, it's robust data, it's robust information, we can easily apply this and we can save the country millions of dollars and we make patients feel a lot better."
He said an incorrect asthma diagnosis can lead to improper treatment which can worsen the condition.