Journal of the Medical Association of Thailand Vol 95, No 11:NOVEMBER 2012 0125-2208 95 11 2012 Nov Spirometric Airflow Obstruction in Bangkok School Children: Prevalence and Risk Factors 1411 EN Supitra Suwanpromma Charoon Boonlarbtaweechoke Umaporn Udomsubpayakul Arunwan Preutthipan Original Article Determine the prevalence of airflow obstruction in schoolchildren in Bangkok and identify its risk factors. Schoolchildren, aged 6 to 18 years, were randomly selected from six schools in central Bangkok. Parents of the children completed a questionnaire. Standard spirometry was performed. Children were classified as having airflow obstruction if FEV1/FVC ratio was < 0.8. Children with FEV1/FVC ratio ≥ 0.8, matched by sex, age, weight, and height, were randomly selected and classified as having no airflow obstruction. Risk factors were identified by univariate and multivariate analyses. Among 1,065 children assessed by spirometry, 43 (4%) demonstrated airflow obstruction. Only three factors including wheezing apart from cold in the past 12 months (OR, 12.82; 95% CI, 1.3-126.5), family history of allergic rhinitis (OR, 2.54; 95% CI, 1.21-5.32), and starting infant formula since birth (OR, 2.47; 95% CI, 1.21-5.04) were shown to be significant risk factors associated with airflow obstruction. The prevalence of airflow obstruction in schoolchildren is lower than those reported in most adult studies. Asthma and family history of allergic rhinitis are important risk factors associated with airflow obstruction. Exclusively breastfeeding since birth might be another helpful measure to prevent the development of airflow obstruction in children. Airflow obstruction Spirometry Children Asthma Allergy Breastfeeding