Objective: To analyze the prevalence of asthma and asthma symptoms in students of two distinct age brackets residing in the city of Tangará da Serra, Brazil.
Methods: Cross-sectional, population-based study of the prevalence of asthma in children from 6 to 7 years of age and adolescents from 13 to 14, using the standardized International Study of Asthma and Allergies in Childhood, phase 1 questionnaire, validated for use in Brazil. Students who responded affirmatively to question 2 (presence of wheezing in the preceding 12 months) were classified as suffering from asthma.
Results: The study comprised 3,362 students, of whom 1,634 (48.6%) were children and 1,728 (51.4%) were adolescents. Of the 1,634 children, 816 (49.9%) were male, and 818 (50.1%) were female. Of the 1,728 adolescents, 773 (45.0%) were male, and 955 (55.0%) were female. The prevalence of asthma among the children was 25.2%, whereas that among the adolescents was 15.9% (chi2 = 8.34; p = 0.00). The children presented higher prevalences of the following symptoms of asthma than did the adolescents: wheezing ever (54.3%), nocturnal dry cough (43.9%), wheezing in the preceding 12 months (25.2%), and from 1 to 3 attacks of wheezing in the preceding 12 months (19.1%). There were no differences between the two groups regarding physician-diagnosed asthma (approximately 4.5%). There were no statistical differences regarding the prevalence of asthma by gender in the two groups.
Conclusions: Tangará da Serra has a high prevalence of asthma in children and adolescents, and this result is compatible with other studies carried out in Brazil and Latin America using the same methodology.