Ethnic differences in time trends in asthma prevalence in New Zealand: ISAAC Phases I and III

The International Study of Asthma and Allergies in Childhood (ISAAC) Phase III survey, New Zealand.

To assess the prevalence of asthma symptoms and time trends by ethnicity between ISAAC Phase I (1992-1993) and Phase III (2001-2003).

Information on asthma symptoms and environmental exposures was collected in children aged 6-7 years (n = 10,873) and adolescents aged 13-14 years (n = 13,317).

In children, the prevalence of current wheeze was 28.5% in Māori (prevalence odds ratio [POR] = 1.49, 95%CI 1.32-1.68), and 25.2% in Pacific Islanders (POR 1.28, 95%CI 1.07-1.54) compared with 20.7% in Europeans/Pakeha. In adolescents, 29.9% of Māori (POR = 1.13, 95%CI 1.03-1.23) and 20.8% of Pacific Islanders (POR 0.74, 95%CI 0.62-0.87) experienced current wheeze compared to 28.6% of Europeans/Pakeha. Between Phases I and III, the prevalence of current wheeze increased significantly by 0.49%/year in Pacific Islanders, increased non-significantly by 0.12%/year in Māori, and decreased significantly by 0.25%/year in Europeans/Pakeha children. In adolescents, the prevalence of current wheeze increased by 0.05%/year in Pacific Islanders and decreased by 0.33%/year in Europeans/Pakeha and by 0.07%/year in Māori.

Ethnic differences in asthma symptom prevalence in New Zealand have increased. The reasons for this are unclear, but may reflect inequalities in access to health services.