Validation of a preschool-based written questionnaire for asthma case identification in Argentina

Asthma remains a significant problem with under diagnosis problematic in many parts of the world. Screening populations at risk is an important strategy to improve diagnosis and reduce the community burden imposed by asthma. In the present study we sought to develop a questionnaire to screen which pre-school aged children required further investigation for the diagnosis and management of asthma, for the first time in Latin-America. A focus group of parents with preschool-aged children with asthma was held to refine symptom description. Questionnaires, in Spanish, were distributed to all parents of children attending 6 randomly selected kindergartens in Trelew, Argentina (n=639). These asked about respiratory symptoms including cough, wheeze, difficulty breathing, exercised-induced symptoms and diagnosed asthma and were filled out at home by parents, A subset of 187 performed a reliability test (test-retest) who completed the same questionnaire twice within 2-5 weeks. Children underwent a clinical assessment, including a standardized history and physical examination, spirometry before and after a β-agonist inhaler, and chest x-ray. Asthma was diagnosed using normal clinical judgment. Mean age of children was 4.21 years (range 3.0-5.5) and included 82.5% white and 49.4% male. Asthma was diagnosed in 103/607 (17.0%); with 72 (69.9%) being new diagnoses. The best combination of items had a sensitivity, specificity, positive predictive value and negative predictive value of 93.20%, 86.11%, 57.83% and 98.41%, respectively. We have demonstrated the utility of a screening questionnaire for determining which preschool-aged children are likely to have asthma and which are not.