Differences in prevalence of asthma, rhinitis, and eczema between parental and self-completed questionnaires in adolescents.

This study was undertaken to compare, for the first time in a developing country, the prevalence of asthma, rhinitis, and eczema in children aged 13-14 years when questionnaires from the International Study of Asthma and Allergies in Childhood (ISAAC) were independently completed by children and parents. A random sample of 3,178 children completed the ISAAC questionnaire at school, while in another sample of 3,387 children, the questionnaire was completed by their parents at home. The prevalence of asthma, rhinitis, and eczema symptoms was significantly higher when questionnaires were completed by adolescents themselves rather than by the parents, particularly for those symptoms that could be better perceived by children or that were more severe, e.g., wheezing with exercise, severe episodes of wheezing, nocturnal cough, and awaking with wheezing in the last 12 months. The diagnosis of hay fever and eczema was also reported more frequently by adolescents compared to their parents. The prevalence of asthma ever and wheezing in the last 12 months was not significantly different between the two samples. In a randomly selected subset of 550 pairs where adolescents and parents came from the same family, asthma ever had the highest agreement (kappa = 0.72, 95% CI: 0.64-0.80), but agreement was poor for rhinitis and eczema ever. In conclusion, the prevalence of asthma, rhinitis, and eczema symptoms varied according to whether the information was reported by independent samples of adolescent or parents. However, the prevalence of wheezing in the last 12 months and asthma ever was quite similar between adolescents and parents, suggesting that these questions are crucial for assessing asthma in epidemiological studies.