Characterizing and Quantifying the Symptomatic Features of COPD Exacerbations

An exacerbation appears to be a quantitative rather than qualitative change from the stable state. This analysis identified a range of symptoms that form a unidimensional construct of overall exacerbation severity. The 14 items identified form the Exacerbations of Chronic Pulmonary Disease Tool (EXACT), a daily diary for detecting and quantifying exacerbation severity in COPD.