Journal Article

Clinical Implications of Having Reduced Mid Forced Expiratory Flow Rates (FEF25-75), Independently of FEV1, in Adult Patients with Asthma

Wenzel, Sally E., Chung, Kian Fan, Castro, Mario, Israel, Elliot, Peters, Stephen P., Moore, Wendy C., Busse, William W., Erzurum, Serpil C., Bleecker, Eugene R., Sorkness, Ronald, Holguin, Fernando, Calhoun, William J., Gaston, Benjamin, Jarjour, Nizar N., Riley, Craig M., Teague, W. Gerald, Fitzpatrick, Anne M.

2015

Overview

FEF25-75 is one of the standard results provided in spirometry reports; however, in adult asthmatics there is limited information on how this physiological measure relates to clinical or biological outcomes independently of the FEV1 or the FEV1/FVC ratio. To determine the association between Hankinson's percent-predicted FEF25-75 (FEF25-75%) levels with changes in healthcare utilization, respiratory symptom frequency, and biomarkers of distal airway inflammation. In participants enrolled in the Severe Asthma Research Program 1-2, we compared outcomes across FEF25-75% quartiles. Multivariable analyses were done to avoid confounding by demographic characteristics, FEV1, and the FEV1/FVC ratio. In a sensitivity analysis, we also compared outcomes across participants with FEF25-75% below the lower limit of normal (LLN) and FEV1/FVC above LLN. Subjects in the lowest FEF25-75% quartile had greater rates of healthcare utilization and higher exhaled nitric oxide and sputum eosinophils. In multivariable analysis, being in the lowest FEF25-75% quartile remained significantly associated with nocturnal symptoms (OR 3.0 [95%CI 1.3-6.9]), persistent symptoms (OR 3.3 [95%CI 1-11], ICU admission for asthma (3.7 [1.3-10.8]) and blood eosinophil % (0.18 [0.07, 0.29]). In the sensitivity analysis, those with FEF25-75%

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adult / Adults / Airway management / Asthma / Asthma - complications / Asthma - physiopathology / Biomarkers / Biomarkers - metabolism / Blood / Bronchial Hyperreactivity - complications / Bronchial Hyperreactivity - physiopathology / Care and treatment / Critical care / Demographic variables / Demographics / Diagnosis / Drug dosages / Emergency medical care / Emergency medical services / Emergency response / Eosinophilia / Eosinophils / Female / Flow rates / Forced Expiratory Flow Rates / Forced Expiratory Volume / Health aspects / Health care / Humans / Hyperreactivity / Hypersensitivity / Leukocytes (eosinophilic) / Male / Management / Medicine / Methacholine / Middle Aged / Morbidity / Multivariate Analysis / Nitric oxide / Odds Ratio / Pediatrics / Physiological aspects / Public health / Pulmonary function tests / Quartiles / Respiratory tract / Respiratory tract diseases / Risk factors / Sensitivity analysis / Sputum / Steroids / Young Adult