RISK-FACTORS FOR ASTHMA SYMPTOMS IN KAWERAU CHILDREN

Aims. To study risk factors for asthma prevalence in Kawerau children aged 8-13 years. Methods. Questionnaires on asthma symptoms and risk f actors were completed in 1992 by parents of 708 Kawerau schoolchildren aged 8-13 years, a response rate of 82.0%; for a subgroup of children , stored serum samples from a 1984 survey were also analysed. Results. The overall prevalence of current wheeze (21.3%) was similar to that observed in other New Zealand surveys. The prevalence of current wheez e was elevated in males (odds ratio (OR) = 1.7, 95% CI 1.2-2.5), in th ose who had been passively exposed to cigarette smoke from the primary caregiver (OR = 1.4, 95% CI 1.0-2.1), in those who had had pets in th e home at age 0-5 years (OR = 1.9, 95% CI 1.2-2.9) and in those with o ne or more birth parents with asthma (OR = 2.1, 95% CI 1.4-3.1); curre nt wheeze was less common in those with older children living in the s ame household (for 2 or more older children in the same household, OR = 0.5, 95% CI 0.2-1.0). In a small nested case-control study it was fo und that current wheeze was more common in those with high levels of I gE (OR = 6.4, 95% CI 1.3-36.4) or low levels of selenium (OR = 3.1, 95 % CI 0.9-11.8) in stored serum collected 8 years previously. There was no difference in the proportions with current wheeze, or with diagnos ed asthma between Maori and European children, but Maori children were more likely to have current frequent nocturnal wheeze (OR = 2.2, 95% CI 1.0-5.1), current severe wheeze (OR = 1.8, 95% CI 0.8-3.7) or to ha ve been admitted to hospital with asthma (OR = 2.4, 95% CI 1.2-4.8). P assive exposure to tobacco smoke was more common among Maori children, but this only partially accounted for the greater asthma severity in Maori children, and the lower prescribing of prophylactic medications in this group may also have contributed. Conclusions. Multiple factors were associated with asthma symptoms in children in this age-group, i ncluding a family history of asthma, male gender, environmental tobacc o smoke, environmental allergen exposure, atopy, and low selenium stat us. Further studies are required to assess the relative contributions of these factors to the prevalence of asthma in New Zealand.