Prevalence of asthma in schoolchildren

OBJECTIVE: To assess the prevalence of asthma symptoms and of asthma in children due to the high frequency of pediatrics patients with symptoms suggestive of the disease and to the lack of data regarding prevalence of asthma in this population. METHODS: We carried out a cross-sectional study with 2,735 school-age children aged 6-7 years and 3,509 adolescents aged 13-14 years selected by random sampling. Data were collected between 1998 and 1999 using a translated version of the questionnaire of the International Study of Asthma and Allergies in Children, which has been previously tested and approved. Guardians were responsible for answering the questionnaire of younger children, whereas adolescents answered their own, in classroom. The data were computed and analyzed using EPI-info software. RESULTS: The response rates for questionnaires were 73.2% (6-7-years old) and 94% (13-14 years old). The prevalence of symptoms in children and adolescents were, respectively: wheezing ever 46.7% and 44.3% (P<0.05); wheezing in the last 12 months 22.7% and 21.2%; speech limited due to wheezing 4.7% and 4.0%; wheezing following exercise 6.3% and 18.2% (P<0.05); nighttime cough in the last 12 months 38.5% and 45.8% (P<0.05); asthma (bronchitis) ever 28.2% and 26.4% (P=0.11). CONCLUSIONS: The prevalence of asthma symptoms and of asthma of the two groups are among the highest results ever reported in Brazil; these results were compatible with those of high prevalence results reported worldwide using ISAAC questionnaires. The high prevalence of symptoms suggests a high prevalence of the disease, which makes asthma an important problem for public health in the region.