PT - JOURNAL ARTICLE AU - G C Donaldson AU - J A Wedzicha TI - COPD exacerbations ยท 1: Epidemiology AID - 10.1136/thx.2005.041806 DP - 2006 Feb 01 TA - Thorax PG - 164--168 VI - 61 IP - 2 4099 - http://thorax.bmj.com/content/61/2/164.short 4100 - http://thorax.bmj.com/content/61/2/164.full SO - Thorax2006 Feb 01; 61 AB - The epidemiology of exacerbations of chronic obstructive pulmonary disease (COPD) is reviewed with particular reference to the definition, frequency, time course, natural history and seasonality, and their relationship with decline in lung function, disease severity and mortality. The importance of distinguishing between recurrent and relapsed exacerbations is discussed.