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American Thoracic Society/European Respiratory Society 2005 standardization of DL CO measurement: Impact on performance
Author(s) -
LEUNG Simon Kwok Fai,
YEW Wing Wai,
WONG Poon Chuen,
TSE Yee Kit,
LAW Wing Sze,
LEUNG Chi Chiu
Publication year - 2008
Publication title -
respirology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 85
eISSN - 1440-1843
pISSN - 1323-7799
DOI - 10.1111/j.1440-1843.2008.01312.x
Subject(s) - medicine , test (biology) , nuclear medicine , physical therapy , paleontology , biology
Background and objective: An updated standardization statement on measurement of DL CO was issued by the American Thoracic Society (ATS)/European Respiratory Society (ERS) Task Force in 2005. The aim of this study was to evaluate the effects of new recommendations on the success rate, test efficiency, measurement variability and reported results of DL CO testing. Methods: We prospectively evaluated 55 Chinese patients without previous experience of the DL CO test in 2006. Performance and results of the test according to the ATS 1995 and ATS/ERS 2005 acceptability criteria were compared. Results: Using the 2005 criteria, the success rate (maximum four trials) improved from 65% to 85% (change: 20%, 95% CI: 9–31%; P = 0.001). The test efficiency as measured by two‐trial and three‐trial success rates increased from 25% and 51% to 60% and 78%, respectively (both P < 0.0005). The measurement variability was defined as the mean of absolute differences between two acceptable trial results of DL CO for each patient. The means (SD) were 0.60 (0.53) and 0.53 (0.57) mL/min/mm Hg for the old and new criteria, respectively ( P = 0.623). The mean DL CO decreased slightly by 0.5%, from 14.93 ± 5.74 (SD) (old criteria) to 14.86 ± 5.75 mL/min/mm Hg (new criteria) overall, with a mean difference (SD) of −0.07 (0.20) mL/min/mm Hg for the 36 subjects meeting both criteria (paired t ‐test, P = 0.048). Conclusions: Success rate and test efficiency for DL CO measurement were improved when the new recommendations were adopted. The effects on measurement variability and reported results were minimal.