Clinical definition of COPD exacerbations and classification of their severity.

A standardized definition of chronic obstructive pulmonary disease (COPD) exacerbation still represents an unmet need in respiratory medicine; definitions currently rely on clinical empiricism with little evidence-based scientific support. Exacerbations of COPD are certainly clear events in the mind of practicing physicians. However, when one tries to provide simple concepts such as their definition and classification of severity, one realizes how little we know. Current symptom- and event-based definitions of a COPD exacerbation, as well as the classifications of the severity of COPD exacerbations, all have their own limitations. Efforts to assess the efficacy of new therapies in the treatment and prevention of COPD exacerbations have been hampered by the lack of a widely agreed upon and consistently used definition. There is a need for greater investment in research on COPD exacerbations in order to promote a better understanding of COPD exacerbations.