Asthma symptoms are found in one in five young New Zealand European children, a quarter of Pacific Island children and nearly a third of Mäori, an international survey has found.
And the differences between children of different ethnicities have widened when compared with the same survey conducted a decade earlier, according to research published by Dr Lis Ellison-Loschmann, from the University’s Centre for Public Health Research.
The survey involved written questionnaires for just over 10,000 children aged six and seven, filled out by their parents or caregivers; and self-completed written and video questionnaires for more than 13,000 13 and 14-year-olds.
It is part of an international survey carried out between 2001 and 2003 and was conducted in five parts of New Zealand – Auckland, Bay of Plenty, Wellington, Nelson and Christchurch.
Among children, 28.5 per cent of Maori had asthma symptoms, up 3 per cent from the earlier study; Pacific children showing symptoms increased by nearly 7 per cent to 25.2 per cent; while the numbers showing symptoms among European/Pakeha children had fallen by 7 per cent to 20.7 per cent.
The survey was carried out as part of phase three of the International Study of Asthma and Allergies in Childhood, which involves more than a million children in more than 100 countries. The study is led by Professor Innes Asher of Auckland University, while Dr Ellison-Loschmann is the lead author for the analysis of ethnic differences in New Zealand.
She says the findings are striking. "When the same survey was done in 1992-1993, the ethnic differences were smaller. Since then, asthma symptom prevalence has stayed the same or increased in Maori and Pacific children, but has decreased in Pakeha children. So now we have big ethnic differences, particularly for younger children, which didn’t exist 15 years ago.”
Environmental factors such as parental smoking, breastfeeding, family size, use of paracetamol and antibiotics do not explain the disparity in differences, Dr Ellison-Loschmann says.
“Differences in asthma prevalence and severity in Mäori may therefore not be due to a higher incidence but rather to a longer duration of the condition resulting from reduced access to care.”
Ethnic inequalities may also have been exacerbated by variations in the access to asthma education, she says. Inappropriate treatment, an inability to afford medicines prescribed or inadequate advice on how to manage the condition may also be contributory factors in its prevalence among Mäori.
Professor Neil Pearce, the director of the centre, says the time taken to issue the findings after conducting the latest survey is due to its broad international scope, with the results of 250 separate centres having to be collated worldwide.
Dr Ellison-Loschmann cautioned against a direct comparison of the asthma symptom prevalence between the two age groups because of the different reporting methods. A consistently lower prevalence level observed in the six and seven-year-olds may be attributable to parents being unlikely to have seen all episodes of wheezing in their children, whereas the 13 and 14-year-olds answered for themselves.
The study is published in the International Journal of Tuberculosis and Lung Disease