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A novel approach for quality control of total lung capacity in the clinical pulmonary function laboratory: A study in a veteran population
Author(s) -
SCHÜNEMANN Holger J.,
DMOCHOWSKI Jacek,
CAMPBELL Lucy A.,
GRANT Brydon J. B.
Publication year - 2003
Publication title -
respirology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 85
eISSN - 1440-1843
pISSN - 1323-7799
DOI - 10.1046/j.1440-1843.2003.00487.x
Subject(s) - medicine , chromatography , spirometry , pulmonary function testing , lung volumes , lung , chemistry , asthma
Objective: Quality control in the clinical pulmonary function laboratory has been well developed for spirometry and diffusing capacity but not for the measurement of TLC. The purpose of the present study was to test two approaches to this problem. First, we compared TLC by body plethysmography (TLC b ) with a value predicted from TLC measured by multibreath helium dilution (TLC m ). Concordance between the measured and predicted values would imply the validity of the measurements. Second, we measured the test–retest variability of TLC b , TLC m and TLC measured by single breath helium dilution (TLC s ) to assess the consistency of the measurements. Methodology: We performed a prospective study of 815 veterans. Results: The prediction of TLC b from TLC m improved ( r 2 increased from 0.44 to 0.64) when FEV 1 /FVC and the difference between TLC m and TLC s were added to the model. The coefficient of variation for test–retest of TLC s , TLC m and TLC b were 8.9, 7.1 and 5.4%, respectively. Of all tests, 5.9% were inconsistent based on pathophysiology or measurement error and attributed mostly to TLC m . Conclusions: Prediction of TLC b from TLC m was not sufficiently accurate as to be useful for quality control. Comparison of TLC s , TLC m and TLC b may be useful for determining the internal data validity.