The burden of child asthma in New Zealand hospitals has increased sharply, prompting a chest expert to warn that more must be done to control the potentially fatal disease.
The proportion of children admitted to hospital with the breathing disease increased by nearly half in 14 years, according to a Massey University study.
The hospital admission rates for the disease are more than twice as high for Maori and more than three times as high for Pacific Islanders than they are for other ethnicities. And they were more than twice as high in the poorest areas than in the wealthiest.
As winter nears, health authorities are worried New Zealand may be in for bad season of influenza viruses, following trends in the Northern Hemisphere.
Respiratory viruses are a common trigger of asthma symptoms - as are cigarette smoke, nitrogen dioxide from gas heaters and car exhausts, and indoor dampness and mould.
"With the onset of cold and flu season, it is critical that adult asthmatics and parents watch out for asthma symptoms, which may signal a potentially deadly attack," said chest expert Associate Professor Jim Reid, of the University of Otago, who is also a medical adviser to the Asthma and Respiratory Foundation.
"As the temperature drops at this time of year, cold air can cause constriction of airways which is also a risk factor for asthmatics. It is important to maintain a temperature of around 20 degrees in the home."
Reid said New Zealand had one of the highest rates of asthma in the world and about 70 people died from the disease each year.
"While we don't fully understand why the rates of asthma are so high among New Zealand adults and children, more needs to be done to get asthma under control.
"If asthmatics begin to exhibit an increasing wheeze that doesn't respond to a reliever inhaler, which is usually blue, they have difficulty speaking in full sentences or they begin to turn blue - these are all signs they need immediate medical intervention."
May 1 is World Asthma Day. Internationally it is estimated that 340 million people are affected by the chronic disease.
University of Auckland paediatrician Professor Innes Asher, chairman of the Global Asthma Network, said: "Asthma affects people of all ages in all parts of the world. Symptoms can include significant difficulty in breathing, which makes ordinary activities extraordinarily hard.
"There are high costs of poorly controlled asthma, including for acute treatment at the doctor, health centre or hospital, lost productivity of people with asthma or parents of children with asthma, and lost education of children who are too unwell to attend school. This amounts to billions of dollars lost to society."
Reid said the key to getting Kiwis' asthma under control is a questionnaire on the effects of symptoms.
The test can be taken at pharmacies, doctors' clinics and at a website run by an asthma medicine supplier.
Reid urged people using an asthma reliever inhaler more than three times a week to take the test and to see their healthcare provider to get the illness under control.
Asthma in New Zealand
• 45 per cent increase in rate of child hospital admissions for asthma in 14 years
• 473 admissions per 100,000 children aged under 15 in 2002
• 688 admissions per 100,000 children aged under 15 in 2016
• 6000 admissions of children under 15 in 2016
• 15 per cent of children have asthma
• 25 per cent of Maori and Pacific Island children have asthma
• 11 per cent of adults have asthma
• 70 - approximate annual asthma death toll
• More than 521,000 people are estimated to need medication for asthma
• More than $850 million - the annual cost to society of asthma, including medical treatment and lost productivity