Eligibility for anti-fibrotic treatment in idiopathic pulmonary fibrosis depends on the predictive equation used for pulmonary function testing

Andrew Burgess, Ken Goon, John D. Brannan, John Attia, Kerrin Palazzi, Christopher Oldmeadow, Tamera J. Corte, Ian Glaspole, Nicole Goh, Gregory Keir, Heather Allan, Sally Chapman, Wendy Cooper, Samantha Ellis, Peter Hopkins, Yuben Moodley, Paul Reynolds, Chris Zappala, Sacha Macansh, Christopher Grainge

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Background and objective: Publicly funded therapy for idiopathic pulmonary fibrosis (IPF) relies on percentage predicted values from pulmonary function testing, for example Australian patients must have a forced vital capacity ≥50% (%FVC), transfer factor of the lung for carbon monoxide ≥ 30% (%TLco) and forced expiratory volume in 1 s (FEV 1 )/FVC ratio > 0.7. Despite defined cut-off values, no jurisdiction prescribes a reference equation for use; multiple equations exist. We hypothesized that access to subsidized treatment varies depending on the chosen equation. The %FVC and %TLco from different commonly used reference equations across general respiratory patients, and IPF-specific patients, were compared. Methods: FVC and TLco measurements from a large general respiratory laboratory and the Australian Idiopathic Pulmonary Fibrosis Registry (AIPFR) database were analysed using multiple equations. Differences between %FVC and %TLco for each equation were calculated, with particular interest in classification of patients (%) at the threshold for subsidized treatment. Results: A total of 20 378 general respiratory database results were analysed. The %FVC ≥ 50% increased from 86% with the Roca equation to 96% with Quanjer (European Coal and Steal Community, ECSC) and %TLco≥30% increased from 91% with Paoletti to 98% with Thompson. However, overall increase in eligibility for subsidized treatment was modest, varying from 48.2% to 49.2%. A total of 545 AIPFR database results were analysed. The %FVC ≥ 50% increased from 73% with Roca to 94% with Quanjer (ECSC) and %TLco≥30% increased from 87% with Paoletti to 96% with Miller. Overall eligibility for subsidized treatment in the AIPFR group varied from 73.6% to 82.8% between surveyed interstitial lung disease (ILD) centres based entirely on the equation used. Conclusion: Substantial variability exists between reference equations, impacting access to subsidized treatment. Treating clinicians should be aware of this when assessing patients around public funding thresholds.

Original languageEnglish
Number of pages8
JournalRespirology
DOIs
Publication statusAccepted/In press - 1 Jan 2019

Keywords

  • fibrosis
  • lung function
  • predicted equations
  • treatment

Cite this

Burgess, Andrew ; Goon, Ken ; Brannan, John D. ; Attia, John ; Palazzi, Kerrin ; Oldmeadow, Christopher ; Corte, Tamera J. ; Glaspole, Ian ; Goh, Nicole ; Keir, Gregory ; Allan, Heather ; Chapman, Sally ; Cooper, Wendy ; Ellis, Samantha ; Hopkins, Peter ; Moodley, Yuben ; Reynolds, Paul ; Zappala, Chris ; Macansh, Sacha ; Grainge, Christopher. / Eligibility for anti-fibrotic treatment in idiopathic pulmonary fibrosis depends on the predictive equation used for pulmonary function testing. In: Respirology. 2019.
@article{dd962da7c0ad4150b5687d4a44fc32a8,
title = "Eligibility for anti-fibrotic treatment in idiopathic pulmonary fibrosis depends on the predictive equation used for pulmonary function testing",
abstract = "Background and objective: Publicly funded therapy for idiopathic pulmonary fibrosis (IPF) relies on percentage predicted values from pulmonary function testing, for example Australian patients must have a forced vital capacity ≥50{\%} ({\%}FVC), transfer factor of the lung for carbon monoxide ≥ 30{\%} ({\%}TLco) and forced expiratory volume in 1 s (FEV 1 )/FVC ratio > 0.7. Despite defined cut-off values, no jurisdiction prescribes a reference equation for use; multiple equations exist. We hypothesized that access to subsidized treatment varies depending on the chosen equation. The {\%}FVC and {\%}TLco from different commonly used reference equations across general respiratory patients, and IPF-specific patients, were compared. Methods: FVC and TLco measurements from a large general respiratory laboratory and the Australian Idiopathic Pulmonary Fibrosis Registry (AIPFR) database were analysed using multiple equations. Differences between {\%}FVC and {\%}TLco for each equation were calculated, with particular interest in classification of patients ({\%}) at the threshold for subsidized treatment. Results: A total of 20 378 general respiratory database results were analysed. The {\%}FVC ≥ 50{\%} increased from 86{\%} with the Roca equation to 96{\%} with Quanjer (European Coal and Steal Community, ECSC) and {\%}TLco≥30{\%} increased from 91{\%} with Paoletti to 98{\%} with Thompson. However, overall increase in eligibility for subsidized treatment was modest, varying from 48.2{\%} to 49.2{\%}. A total of 545 AIPFR database results were analysed. The {\%}FVC ≥ 50{\%} increased from 73{\%} with Roca to 94{\%} with Quanjer (ECSC) and {\%}TLco≥30{\%} increased from 87{\%} with Paoletti to 96{\%} with Miller. Overall eligibility for subsidized treatment in the AIPFR group varied from 73.6{\%} to 82.8{\%} between surveyed interstitial lung disease (ILD) centres based entirely on the equation used. Conclusion: Substantial variability exists between reference equations, impacting access to subsidized treatment. Treating clinicians should be aware of this when assessing patients around public funding thresholds.",
keywords = "fibrosis, lung function, predicted equations, treatment",
author = "Andrew Burgess and Ken Goon and Brannan, {John D.} and John Attia and Kerrin Palazzi and Christopher Oldmeadow and Corte, {Tamera J.} and Ian Glaspole and Nicole Goh and Gregory Keir and Heather Allan and Sally Chapman and Wendy Cooper and Samantha Ellis and Peter Hopkins and Yuben Moodley and Paul Reynolds and Chris Zappala and Sacha Macansh and Christopher Grainge",
year = "2019",
month = "1",
day = "1",
doi = "10.1111/resp.13540",
language = "English",
journal = "Respirology",
issn = "1323-7799",
publisher = "John Wiley & Sons",

}

Burgess, A, Goon, K, Brannan, JD, Attia, J, Palazzi, K, Oldmeadow, C, Corte, TJ, Glaspole, I, Goh, N, Keir, G, Allan, H, Chapman, S, Cooper, W, Ellis, S, Hopkins, P, Moodley, Y, Reynolds, P, Zappala, C, Macansh, S & Grainge, C 2019, 'Eligibility for anti-fibrotic treatment in idiopathic pulmonary fibrosis depends on the predictive equation used for pulmonary function testing' Respirology. https://doi.org/10.1111/resp.13540

Eligibility for anti-fibrotic treatment in idiopathic pulmonary fibrosis depends on the predictive equation used for pulmonary function testing. / Burgess, Andrew; Goon, Ken; Brannan, John D.; Attia, John; Palazzi, Kerrin; Oldmeadow, Christopher; Corte, Tamera J.; Glaspole, Ian; Goh, Nicole; Keir, Gregory; Allan, Heather; Chapman, Sally; Cooper, Wendy; Ellis, Samantha; Hopkins, Peter; Moodley, Yuben; Reynolds, Paul; Zappala, Chris; Macansh, Sacha; Grainge, Christopher.

In: Respirology, 01.01.2019.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Eligibility for anti-fibrotic treatment in idiopathic pulmonary fibrosis depends on the predictive equation used for pulmonary function testing

AU - Burgess, Andrew

AU - Goon, Ken

AU - Brannan, John D.

AU - Attia, John

AU - Palazzi, Kerrin

AU - Oldmeadow, Christopher

AU - Corte, Tamera J.

AU - Glaspole, Ian

AU - Goh, Nicole

AU - Keir, Gregory

AU - Allan, Heather

AU - Chapman, Sally

AU - Cooper, Wendy

AU - Ellis, Samantha

AU - Hopkins, Peter

AU - Moodley, Yuben

AU - Reynolds, Paul

AU - Zappala, Chris

AU - Macansh, Sacha

AU - Grainge, Christopher

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Background and objective: Publicly funded therapy for idiopathic pulmonary fibrosis (IPF) relies on percentage predicted values from pulmonary function testing, for example Australian patients must have a forced vital capacity ≥50% (%FVC), transfer factor of the lung for carbon monoxide ≥ 30% (%TLco) and forced expiratory volume in 1 s (FEV 1 )/FVC ratio > 0.7. Despite defined cut-off values, no jurisdiction prescribes a reference equation for use; multiple equations exist. We hypothesized that access to subsidized treatment varies depending on the chosen equation. The %FVC and %TLco from different commonly used reference equations across general respiratory patients, and IPF-specific patients, were compared. Methods: FVC and TLco measurements from a large general respiratory laboratory and the Australian Idiopathic Pulmonary Fibrosis Registry (AIPFR) database were analysed using multiple equations. Differences between %FVC and %TLco for each equation were calculated, with particular interest in classification of patients (%) at the threshold for subsidized treatment. Results: A total of 20 378 general respiratory database results were analysed. The %FVC ≥ 50% increased from 86% with the Roca equation to 96% with Quanjer (European Coal and Steal Community, ECSC) and %TLco≥30% increased from 91% with Paoletti to 98% with Thompson. However, overall increase in eligibility for subsidized treatment was modest, varying from 48.2% to 49.2%. A total of 545 AIPFR database results were analysed. The %FVC ≥ 50% increased from 73% with Roca to 94% with Quanjer (ECSC) and %TLco≥30% increased from 87% with Paoletti to 96% with Miller. Overall eligibility for subsidized treatment in the AIPFR group varied from 73.6% to 82.8% between surveyed interstitial lung disease (ILD) centres based entirely on the equation used. Conclusion: Substantial variability exists between reference equations, impacting access to subsidized treatment. Treating clinicians should be aware of this when assessing patients around public funding thresholds.

AB - Background and objective: Publicly funded therapy for idiopathic pulmonary fibrosis (IPF) relies on percentage predicted values from pulmonary function testing, for example Australian patients must have a forced vital capacity ≥50% (%FVC), transfer factor of the lung for carbon monoxide ≥ 30% (%TLco) and forced expiratory volume in 1 s (FEV 1 )/FVC ratio > 0.7. Despite defined cut-off values, no jurisdiction prescribes a reference equation for use; multiple equations exist. We hypothesized that access to subsidized treatment varies depending on the chosen equation. The %FVC and %TLco from different commonly used reference equations across general respiratory patients, and IPF-specific patients, were compared. Methods: FVC and TLco measurements from a large general respiratory laboratory and the Australian Idiopathic Pulmonary Fibrosis Registry (AIPFR) database were analysed using multiple equations. Differences between %FVC and %TLco for each equation were calculated, with particular interest in classification of patients (%) at the threshold for subsidized treatment. Results: A total of 20 378 general respiratory database results were analysed. The %FVC ≥ 50% increased from 86% with the Roca equation to 96% with Quanjer (European Coal and Steal Community, ECSC) and %TLco≥30% increased from 91% with Paoletti to 98% with Thompson. However, overall increase in eligibility for subsidized treatment was modest, varying from 48.2% to 49.2%. A total of 545 AIPFR database results were analysed. The %FVC ≥ 50% increased from 73% with Roca to 94% with Quanjer (ECSC) and %TLco≥30% increased from 87% with Paoletti to 96% with Miller. Overall eligibility for subsidized treatment in the AIPFR group varied from 73.6% to 82.8% between surveyed interstitial lung disease (ILD) centres based entirely on the equation used. Conclusion: Substantial variability exists between reference equations, impacting access to subsidized treatment. Treating clinicians should be aware of this when assessing patients around public funding thresholds.

KW - fibrosis

KW - lung function

KW - predicted equations

KW - treatment

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U2 - 10.1111/resp.13540

DO - 10.1111/resp.13540

M3 - Article

JO - Respirology

JF - Respirology

SN - 1323-7799

ER -