Health status measurement in exacerbations of COPD.

This article evaluates recent publications measuring health status in exacerbations of chronic obstructive pulmonary disease (COPD) and sets them in the context of existing knowledge. Limitations of the studies are discussed and the validity of health status measurement for exacerbations in light of new evidence is reviewed. Additional research is required to characterize health status measurement across exacerbation frequencies and to clarify predictive validity according to the definition of an exacerbation. There is also a need for the population composition of future studies to reflect the changing gender prevalence of COPD, investigate exacerbation-related health status in patients classified with mild COPD and incorporate unreported exacerbation events. Challenges in developing new tools for the quantification of exacerbations are outlined and their likely future contribution to health status measurement is discussed.