RESUMO
As developing countries adopt an industrialized style of living, an increase in asthma prevalence can be expected. A cross sectional study was undertaken to evaluate the prevalence rates of asthma and related symptoms and clinical findings in Isfahan, Iran. A randomly selected population of Isfahan primary school children, consisting of 3,982 children aged 6 to 11 was enrolled in the study. Parents completed a Persian questionnaire modified from ISAAC and ECRHS questionnaires. The returned 3,828 (96.1%) questionnaires were reviewed and 686 children suffering from asthma or any of the related symptoms were invited for further evaluations. In this stage 655 children (95.5%) underwent a medical interview and physical examinations, of which 415, underwent post exercise spirometry and body-plethysmography. The prevalence rates for previously diagnosed asthma, dyspnea and wheezing ever, dyspnea and wheezing in the last 12 months and frequently recurring dyspneal attacks were 0.71%, 7.6%, 3.9% and 1.6%, respectively. Wheezing was heard upon auscultation of the chests of 70 children (10.7%). Forced expiratory volume in 1st second (FEV1) < 80% of prediction was recorded in 3.1% of the children, other findings included reduced peak expiratory flow rate (PEF), mean expiratory flow 25 to 75 percent (FEF 25-75), forced expiratory flow at 75% of FVC (FEF 75), and increased residual volume (RV) and air-ways resistance in 4.3%, 10.6%, 21.2%, 30.1% and 63.2% of the pupils, respectively. We conclude that asthma screening programs employing clinical methods should be encouraged, but measurement of airway resistance is not a suitable tool for epidemiologic studies.