Methods: Multicentric, cross-sectional survey. The standardized Spanish-version ISAAC questionnaire was applied to tutors of children aged 6-7 years old in 8 cities of the Mexican Republic. Sample was randomly selected through public and private schools of each city, and a sample of 3000 children per center was advisable. Risk analysis was made through multivariate logistical regression, central tendency and dispersion measures were obtained with respective 95% confidence intervals.
Results: Nine centers of 8 cities participated, data of 24,504 questionnaires were analyzed with an answer rate of 90.7%
Grouping the nine participating centers, a prevalence of 8.4% (95%CI 8.1-8.8%) for wheezing in the last 12 months was found, with the next distribution: Monterrey 8.6% (95%CI 7.6-9.6%), Mexicali 9.6% (95%CI 8.4-10.7%), Ciudad Victoria 8.6% (95%CI 7.5-9.7%), Villahermosa 10.2% (95%CI 9.1-11.4%), Northern Distrito Federal 7.3% (95%CI 6.5-8.2%), Southeast Distrito Federal 9.9% (95%CI 8.5-11.3%), Toluca 5.9% (95%CI 5.1-6.7%), Tijuana 8.2% (95%CI 7.2-9.2%), Veracruz 9.7% (95%CI 8.4-10.9%).
Identified risk factors for the presence of wheezing in the last 12 months were: nasal symptoms accompanied with ocular symptoms (itching and tearing) in the last 12 months, OR 2.31 (95%CI 2.01-2.66; p=<0.0001). Nasal symptoms (blocked nose, runny nose, and/or itching) in the last 12 months, OR 2.2 (95%CI 1.66-2.92; p=<0.0001). Hay fever diagnosis by medical staff OR 2.02 (95%CI 1.72-2.37; p=<0.0001). Atopic dermatitis symptoms (classic morphology and distribution) in the last 12 months, OR 1.65 (95%CI 1.39-1.96; p=<0.0001). Use of antibiotics in the first 12 months of life, OR 1.68 (95%CI 1.48-1.90; p=<0.0001). Use of acetaminophen in the last 12 months, OR 1.49 (95%CI 1.35-1.65; p=<0.0001).
Conclusions: The presence of allergic rhinoconjuntivitis’ symptoms in the last 12 months doubles the risk for the presence of wheezing in Mexican children.