Chest
Volume 132, Issue 2, August 2007, Pages 388-395
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Original Research
Pulmonary Function Testing
Instrument Accuracy and Reproducibility in Measurements of Pulmonary Function

https://doi.org/10.1378/chest.06-1998Get rights and content

Background

The objective of the study was to quantify the accuracy and reproducibility of five commercially available pulmonary function test (PFT) instruments (Collins CPL [Ferraris Respiratory; Louisville, CO]; Morgan Transflow Test PFT System [Morgan Scientific; Haverhill, MA]; SensorMedics V˙max 22D [VIASYS Healthcare; Yorba Linda, CA]; Jaeger USA Masterscreen Diffusion TP [VIASYS Healthcare]; and Medical Graphics Profiler DX System [Medical Graphics Corp; St. Paul, MN]) that are associated with spirometry and the measurement of pulmonary diffusing capacity.

Methods

In a multifactor, single-center, repeated-measures, full factorial 90-day study, a pulmonary waveform generator and a single-breath simulator of diffusing capacity of the lung for carbon monoxide (Dlco) were used to perform simulations of FVC and Dlco maneuvers. Accuracy was assessed as the difference between the observed and simulated values. Reproducibility was determined as the coefficient of variation of all measurements made during the study.

Results

All instruments demonstrated a high degree of accuracy in the measurement of FVC and FEV1. Overall, the accuracies associated with the measurement of peak flow, forced expiratory flow, mid-expiratory phase, and diffusing capacity were generally lower and more variable among the instruments tested. The coefficients of variation of Dlco measurements over 90 days were higher than those observed for spirometry.

Conclusions

This study demonstrates the feasibility of assessing the accuracy and reproducibility of modern PFT instruments using simulation testing. Our results provide an assessment of the component of PFT accuracy and reproducibility that is due to instrumentation alone.

Section snippets

Instruments Tested

This trial was a replicated, fully crossed multifactor, single-center methodology study. The following new instruments were purchased from each of five different manufacturers: Collins CPL (Ferraris Respiratory; Louisville, CO); Morgan Transflow Test PFT System (Morgan Scientific; Haverhill, MA); SensorMedics V˙max 22D (VIASYS Healthcare; Yorba Linda, CA); Jaeger USA Masterscreen Diffusion TP (VIASYS Healthcare); and Medical Graphics Profiler DX System (Medical Graphics Corp; St. Paul, MN).

Results

Tabular summaries of the mean percentage of accuracy of spirometry end points and the mean absolute accuracy of Dlco end points are provided in the on-line supplement to this article.

Discussion

The methodology employed in the current study enabled a uniform assessment of several commercially available PFT instruments in the measurement of spirometry and gas exchange end points. Our results provide insight into the accuracy and reproducibility associated with the measurement of these end points that is due solely to instrumentation.

Instrumentation technology has advanced to the point that the accuracy of spirometric measurements is very similar between instrument models and, in most

ACKNOWLEDGMENT

The authors wish to thank Janet Embry for manuscript review and editing, and Heather Howell and Angie Flint for technical support and data collection. Editorial support was also provided by J. Grice of PAREXEL.

References (17)

There are more references available in the full text version of this article.

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This study was sponsored by Pfizer Inc.

Drs. Jensen and Crapo have been consultants for Pfizer Inc. and have received royalties from Hans Rudolph Company. Drs. Teeter, England, White, and Pickering are employed by Pfizer Inc.

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