Role of FEF25-75 in characterizing outpatients with asthma in clinical practice.

BACKGROUND:Asthma is characterized by variable airflow limitation. FEF25-75 has been proposed as a reliable marker for bronchial obstruction, especially when FEV1 and FEV1/FVC are normal. OBJECTIVES:To investigate the role of FEF25-75 in patients with asthma seen in clinical settings. MATERIALS AND METHODS:The cross-sectional study included 439 (181 females and 255 males; mean age 39 years) outpatients with asthma who consecutively visited an allergy clinic for a routine assessment. History, physical examination, asthma control, and spirometry were evaluated. RESULTS:FEF25-75 was impaired (< 65% of predicted) in 136 (31%) outpatients. Considering only subjects with normal FEV1 and FEV1/FVC, FEF25-75 was impaired in 71 (19.6%) subjects. In this subset, impaired FEF25-75 was associated with low FEV1 and FEV1/FVC values (OR 0.91 and 0.85, respectively), and presence of asthma symptoms (OR 2.19). CONCLUSION:FEF25-75 deserves adequate and careful consideration in patients with asthma and normal FEV1 and FEV1/FVC, as the presence of impaired FEF25-75 in this subset suggests a more specific approach.