Asthma, FEF25–75, and Hospitalizations in Children

Asthma is a common chronic pediatric respiratory disease associated with significant morbidity. Current guidelines recommend monitoring forced expiratory volume in 1 s (FEV 1 ) as part of the assessment of asthma severity and control; however, many children with asthma have a normal FEV 1 despite significant symptoms. Reduced forced expiratory flow between 25%–75% of forced vital capacity (FEF 25–75 ) may be an important measure of asthma severity and control in children with normal FEV 1 . This study examines the association between FEF 25–75 and asthma-related hospitalizations. Pulmonary function tests and records of 925 children ≤19 years of age seen for an initial evaluation of physician-diagnosed asthma at a community-based asthma clinic between 1999 and 2011 were reviewed. FEV 1 ≥80% predicted and FEF 25–75 ≥60% were considered normal. The associations between FEV 1 and FEF 25–75 and asthma-related hospitalizations were examined using logistic regression models. Thirteen percent ( n =118) of the children were hospitalized for asthma at least once in the previous year. Fifty four percent ( n =501) of the children met criteria for uncontrolled asthma symptoms. Asthma-related hospitalization was associated with reducing categories of FEF 25–75 , but not FEV 1 . Among the 693 children with normal FEV 1 (≥80%), those with FEF 25–75