Asthma and wheeze in New Zealand adolescents.

Two epidemiological surveys of New Zealand adolescents are reported. The prevalence of asthma was 7.5 percent in Rotorua and 7.9 percent in Wairoa. Additional questions asked in Wairoa identified 18.2 percent of subjects who had experienced wheeze but had not been labelled "asthma". The association of active asthma with nasal obstruction was confirmed. Wheeze which had not been labelled asthma was associated with the combination of subject's own and maternal cigarette smoking. The use of asthma medication was associated with easier geographic and socio-economic access to medical care, as well as with asthma activity.