Diagnostic and prognostic utility of mid-expiratory flow rate in older community-dwelling persons with respiratory symptoms but without chronic obstructive pulmonary disease

摘要

BackgroundThe maximal expiratory flow at 50 % of the forced vital capacity (MEF50) is the flow where half of forced vital capacity (FVC) remains to be exhaled. A reduced MEF50 has been suggested as a surrogate marker of small airways disease. The diagnostic and prognostic utility of this easy to assess spirometric variable in persons with respiratory symptoms, but without COPD is unclear.