Asthma hospitalisations have fallen 20 percent in four years.

Asthma affects one in eight New Zealanders - and more than 500,000 take medication for their symptoms.

Asthma and Respiratory Foundation CEO Letitia Harding says the drop in hospitalisations is mostly due to a new medication.

"This has actually really been down to a new type of inhaler, which is what we call your two-in-one combination inhaler."

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