Meeraus WH, DeBarmore BM, Mullerova H, Fahy WA, Benson VS. Terms and Definitions Used to Describe Recurrence, Treatment Failure and Recovery of Acute Exacerbations of COPD: A Systematic Review of Observational Studies.
Int J Chron Obstruct Pulmon Dis 2022;
16:3487-3502. [PMID:
34992357 PMCID:
PMC8713707 DOI:
10.2147/copd.s335742]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/23/2021] [Indexed: 11/23/2022] Open
Abstract
Introduction
Acute exacerbations of chronic obstructive pulmonary disease (AECOPDs) are important clinical events, with many patients experiencing multiple AECOPDs annually. The terms used in the literature to define recurring AECOPD events are inconsistent and may impact the ability to describe the true burden of these events. We undertook a systematic review to identify and summarize terms and definitions used in observational studies to describe AECOPD-related events occurring after an initial AECOPD (hereafter “subsequent AECOPD”).
Methods
PubMed was searched (2000–2019) for observational studies on subsequent AECOPD events using broad search strings for “COPD”, “exacerbation”, and “subsequent exacerbation events”. Only English-language studies were included. Small studies (n<50) and studies focusing on hospital re-admission only were excluded. Extracted data were analyzed descriptively to generate a narrative summary, using a thematic approach to group studies utilizing similar terms for subsequent AECOPD.
Results
Forty-seven studies were included. No single, distinct terms or definitions were used to define and identify multiple occurrences of AECOPDs, though most (46) studies used one or more of four clustered terms and definitions: reapse (n = 13), recurrence/re-exacerbation (n = 11), treatment failure (n = 12) and non-recovery/time to recovery (n = 16). Heterogeneity was observed within and between the four clusters with respect to study setting, starting point for observing subsequent AECOPDs, time frame to identify a subsequent AECOPD (except for studies using “time to recovery”), and basis for identifying a subsequent exacerbation.
Conclusion
Our review demonstrates that subsequent AECOPDs (including events such as relapse, recurrence/re-exacerbation, treatment failure, non-recovery/time to recovery) are ill-defined in the observational study literature, emphasizing the need to reach consensus on precise and objective definitions (for example, when one AECOPD ends and another begins). Use of standardized terminology and definitions may aid comparability between, and synthesis of, studies, thus improving the understanding of the natural history and burden of exacerbations in COPD patients.
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