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Background Children spend a significant amount of time in school. Little is known about the role of allergen exposure in school environments and asthma morbidity. Objectives The School Inner-City Asthma (SICAS) is an NIH funded prospective study evaluating the school/classroom specific risk factors and asthma morbidity among urban children Methods/Results This paper describes the design, methods, and important lessons learned from this extensive investigation. A single center is recruiting 500 elementary school aged children, all of whom attend inner-city, metropolitan schools. The primary hypothesis is that exposure to common indoor allergens in the classroom will increase the risk of asthma morbidity in children with asthma, even after controlling for home allergen exposures. The protocol includes screening surveys of entire schools and baseline eligibility assessments obtained in the spring prior to the academic year. Extensive baseline clinical visits are being conducted among eligible children with asthma during the summer prior to the academic school year. Environmental classroom/school assessments including settled dust and air sampling for allergen, mold, air pollution, and inspection data are collected twice during the academic school year and one home dust sample linked to the enrolled student. Clinical outcomes are measured every 3 months during the academic school year. Conclusion The overall goal of SICAS is to complete the first study of its kind to better understand school-specific urban environmental factors on childhood asthma morbidity. We also discuss the unique challenges related to school-based urban research and lessons being learned from recruiting such a cohort.

Objective The forced expiratory volume in one second (FEV1), felt to be an objective measure of airway obstruction, is often normal in asthmatic children. The forced expiratory flow between 25% and 75% of vital capacity (FEF25-75) reflects small airway patency and has been found to be reduced in children with asthma. The aim of this study was to determine if FEF25-75 is associated with increased childhood asthma severity and morbidity in the setting of a normal FEV1, and to determine if bronchodilator responsiveness (BDR) as defined by FEF25-75 identifies more childhood asthmatics than does BDR defined by FEV1. Methods The Children’s Hospital Boston Pulmonary Function Test database was queried and the most recent spirometry result was retrieved for 744 children diagnosed with asthma between 10–18 years of age between October 2000 and October 2010. Electronic medical records in the 1 year prior and the 1 year following the date of spirometry were examined for asthma severity (mild, moderate or severe) and morbidity outcomes for three age, race and gender-matched subgroups: group A (n= 35) had a normal FEV1, FEV1/FVC and FEF25-75; Group B (n= 36) had solely a diminished FEV1/FVC; and Group C (n=37) had a normal FEV1, low FEV1/FVC and low FEF25-75. Morbidity outcomes analyzed included the presence of hospitalization, emergency department visit, intensive care unit admission, asthma exacerbation, and systemic steroid use. Results Subjects with a low FEF25-75 (Group C) had nearly 3 times the odds (OR 2.8, p<0.01) of systemic corticosteroid use and 6 times the odds of asthma exacerbations (OR 6.3, p>0.01) compared with those who had normal spirometry (Group A). Using FEF25-75 to define bronchodilator responsiveness identified 53% more subjects with asthma than did using a definition based on FEV1. Conclusions A low FEF25-75 in the setting of a normal FEV1 is associated with increased asthma severity, systemic steroid use and asthma exacerbations in children. In addition, using the percent change in FEF25-75 from baseline may be helpful in identifying bronchodilator responsiveness in asthmatic children with a normal FEV1.