Cross-sectional survey of risk factors for asthma in 6-7-year-old children in New Zealand: International Study of Asthma and Allergy in Childhood Phase Three.

Aim: To identify risk factors for asthma in primary school-aged children in New Zealand.

Methods: A cross-sectional survey of 10,873 6-7-year-old children in Auckland, Bay of Plenty, Nelson and Christchurch (a response rate of 85.2%). A questionnaire was completed by the parent or care giver.

Results: 22.2% of children wheezed in the last 12 months (current wheeze). Maori children were at greater risk of current wheeze compared with European children (adjusted odds ratio (adjOR) = 1.37; 95% confidence interval = 1.18-1.59). Antibiotics and paracetamol used in the first year of life were associated with an increased risk of current wheeze (adjOR = 1.78 (1.56-2.04) and adjOR = 1.31 (1.06-1.61), respectively). Watching television for 5 or more hours per day was associated with an increased risk of current wheeze (adjOR = 1.44 (1.13-1.83)). Milk and egg consumption in the last 12 months was associated with a reduced risk of current wheeze.

Conclusions:  This study has identified risk factors for asthma in children aged 6-7 years, although causal pathways cannot be established. These associations have important public health implications if causal.