Definitions of Exacerbations Tanja W. Effing, PhD, Huib A.M. Kerstjens, MD, PhD, Evelyn M. Monninkhof, PhD, Paul D.L.P.M. van der Valk, MD, PhD, Emiel F.M. Wouters, MD, PhD, Dirkje S. Postma, MD, PhD, Gerhard A. Zielhuis, PhD, Job van der Palen, PhD  CHEST  Volume 136, Issue 3, Pages 918-923 (September 2009) DOI: 10.1378/chest.08-1680 Copyright © 2009 The American College of Chest Physicians Terms and Conditions

Figure 1 Flow chart of the search strategy. Of the included articles, the context in which the variable “exacerbation” was used is specified, and it is noted whether a definition of an exacerbation was defined. CHEST 2009 136, 918-923DOI: (10.1378/chest.08-1680) Copyright © 2009 The American College of Chest Physicians Terms and Conditions