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Reliability of FEV1/FEV6 to Diagnose Airflow Obstruction Compared with FEV1/FVC: The PLATINO Longitudinal Study.
- Source :
- PLoS ONE; Aug2013, Vol. 8 Issue 8, p1-7, 7p
- Publication Year :
- 2013
-
Abstract
- QUESTION: A 6-second spirometry test is easier than full exhalations. We compared the reliability of the ratio of the Forced expiratory volume in 1 second/Forced expiratory volume in 6 seconds (FEV<subscript>1</subscript>/FEV<subscript>6</subscript>) to the ratio of the FEV<subscript>1</subscript>/Forced vital capacity (FEV<subscript>1</subscript>/FVC) for the detection of airway obstruction. METHODS: The PLATINO population-based survey in individuals aged 40 years and over designed to estimate the prevalence of post-Bronchodilator airway obstruction repeated for the same study participants after 5–9 years in three Latin-American cities. RESULTS: Using the FEV<subscript>1</subscript>/FVC<Lower limit of normal (LLN) index, COPD prevalence apparently changed from 9.8 to 13.2% in Montevideo, from 9.7 to 6.0% in São Paulo and from 8.5 to 6.6% in Santiago, despite only slight declines in smoking prevalence (from 30.8% to 24.3%). These changes were associated with differences in Forced expiratory time (FET) between the two surveys. In contrast, by using the FEV<subscript>1</subscript>/FEV<subscript>6</subscript> to define airway obstruction, the changes in prevalence were smaller: 9.7 to 10.6% in Montevideo, 8.6 to 9.0% in São Paulo, and 7.5 to 7.9% in Santiago. Changes in the prevalence of COPD with criteria based on FEV<subscript>1</subscript>/FVC correlated strongly with changes in the FET of the tests (R<superscript>2</superscript> 0.92) unlike the prevalence based on a low FEV<subscript>1</subscript>/FEV<subscript>6</subscript> (R<superscript>2</superscript> = 0.40). CONCLUSION: The FEV<subscript>1</subscript>/FEV<subscript>6</subscript> is a more reliable index than FEV<subscript>1</subscript>/FVC because FVC varies with the duration of the forced exhalation. Reporting FET and FEV<subscript>1</subscript>/FEV<subscript>6</subscript><LLN helps to understand differences in prevalence of COPD obtained from FEV<subscript>1</subscript>/FVC-derived indices. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 19326203
- Volume :
- 8
- Issue :
- 8
- Database :
- Complementary Index
- Journal :
- PLoS ONE
- Publication Type :
- Academic Journal
- Accession number :
- 90070327
- Full Text :
- https://doi.org/10.1371/journal.pone.0067960