Validation of pre-flight algorithms in predicting hypoxic challenge testing (HCT) outcomes in interstitial lung disease (ILD)

Cameron Bonthrone; Beyazit Durdu; Sarah Mulholland; Naomi Rippon; Louis Luckwell; Michelle Westlake; Giles Dixon; Matthew Wells; Huzaifa Adamali; Shaney L. Barratt

doi:10.1177/17534666261431183

Validation of pre-flight algorithms in predicting hypoxic challenge testing (HCT) outcomes in interstitial lung disease (ILD)

Cameron Bonthrone, Beyazit Durdu, Sarah Mulholland, Naomi Rippon, Louis Luckwell, Michelle Westlake, Giles Dixon, Matthew Wells, Huzaifa Adamali, Shaney L. Barratt^*

^*Corresponding author for this work

Bristol Medical School (THS)

Research output: Contribution to journal › Article (Academic Journal) › peer-review

Abstract

Background:
The British Thoracic Society (BTS) currently recommends pre-flight clinical assessment of all symptomatic patients with interstitial lung disease (ILD). This may include hypoxic challenge testing (HCT) to determine whether supplemental in-flight oxygen is required, but it is not universally available.

Objectives:
(1) To validate a previously published pre-flight assessment algorithm in predicting outcomes of HCT in ILD. (2) Compare the sensitivity and specificity of the original algorithm to an amended version published in the BTS clinical statement on air travel.

Design:
Single centre, cohort study.

Methods:
A single-centre retrospective cohort analysis of ILD patients attending for HCT between March 2017 and April 2023.

Results:
A total of 126 patients with a diagnosis of ILD underwent HCT. Median forced vital capacity 75.0% predicted (interquartile range (IQR) 24.8) and transfer factor for carbon monoxide 45.8% predicted (IQR 18.6). Diagnosis of idiopathic pulmonary fibrosis in 50.8% (n = 64). A total of 18 individuals became hypoxic during the test (a fall of PaO2 to

Original language	English
Article number	17534666261431183
Number of pages	8
Journal	Therapeutic Advances in Respiratory Disease
Volume	20
Early online date	15 Mar 2026
DOIs	https://doi.org/10.1177/17534666261431183
Publication status	E-pub ahead of print - 15 Mar 2026

Bibliographical note

Publisher Copyright:
© The Author(s), 2026.

Research Groups and Themes

Academic Respiratory Unit

Keywords

idiopathic pulmonary fibrosis
interstitial lung disease
air travel
hypoxic challenge test
pulmonary fibrosis

Access to Document

10.1177/17534666261431183Licence: CC BY-NC

Handle.net

Persistent link

Cite this

Bonthrone, C., Durdu, B., Mulholland, S., Rippon, N., Luckwell, L., Westlake, M., Dixon, G., Wells, M., Adamali, H., & Barratt, S. L. (2026). Validation of pre-flight algorithms in predicting hypoxic challenge testing (HCT) outcomes in interstitial lung disease (ILD). Therapeutic Advances in Respiratory Disease, 20, Article 17534666261431183. Advance online publication. https://doi.org/10.1177/17534666261431183

@article{1669cc35a0c146179435643710bfbe51,

title = "Validation of pre-flight algorithms in predicting hypoxic challenge testing (HCT) outcomes in interstitial lung disease (ILD)",

abstract = "Background: The British Thoracic Society (BTS) currently recommends pre-flight clinical assessment of all symptomatic patients with interstitial lung disease (ILD). This may include hypoxic challenge testing (HCT) to determine whether supplemental in-flight oxygen is required, but it is not universally available. Objectives: (1) To validate a previously published pre-flight assessment algorithm in predicting outcomes of HCT in ILD. (2) Compare the sensitivity and specificity of the original algorithm to an amended version published in the BTS clinical statement on air travel. Design: Single centre, cohort study. Methods: A single-centre retrospective cohort analysis of ILD patients attending for HCT between March 2017 and April 2023. Results: A total of 126 patients with a diagnosis of ILD underwent HCT. Median forced vital capacity 75.0\% predicted (interquartile range (IQR) 24.8) and transfer factor for carbon monoxide 45.8\% predicted (IQR 18.6). Diagnosis of idiopathic pulmonary fibrosis in 50.8\% (n = 64). A total of 18 individuals became hypoxic during the test (a fall of PaO2 to",

keywords = "idiopathic pulmonary fibrosis, interstitial lung disease, air travel, hypoxic challenge test, pulmonary fibrosis",

author = "Cameron Bonthrone and Beyazit Durdu and Sarah Mulholland and Naomi Rippon and Louis Luckwell and Michelle Westlake and Giles Dixon and Matthew Wells and Huzaifa Adamali and Barratt, \{Shaney L.\}",

note = "Publisher Copyright: {\textcopyright} The Author(s), 2026.",

year = "2026",

month = mar,

day = "15",

doi = "10.1177/17534666261431183",

language = "English",

volume = "20",

journal = "Therapeutic Advances in Respiratory Disease",

issn = "1753-4666",

publisher = "SAGE Publications Ltd",

}

Bonthrone, C, Durdu, B, Mulholland, S, Rippon, N, Luckwell, L, Westlake, M, Dixon, G, Wells, M, Adamali, H & Barratt, SL 2026, 'Validation of pre-flight algorithms in predicting hypoxic challenge testing (HCT) outcomes in interstitial lung disease (ILD)', Therapeutic Advances in Respiratory Disease, vol. 20, 17534666261431183. https://doi.org/10.1177/17534666261431183

TY - JOUR

T1 - Validation of pre-flight algorithms in predicting hypoxic challenge testing (HCT) outcomes in interstitial lung disease (ILD)

AU - Bonthrone, Cameron

AU - Durdu, Beyazit

AU - Mulholland, Sarah

AU - Rippon, Naomi

AU - Luckwell, Louis

AU - Westlake, Michelle

AU - Dixon, Giles

AU - Wells, Matthew

AU - Adamali, Huzaifa

AU - Barratt, Shaney L.

PY - 2026/3/15

Y1 - 2026/3/15

N2 - Background: The British Thoracic Society (BTS) currently recommends pre-flight clinical assessment of all symptomatic patients with interstitial lung disease (ILD). This may include hypoxic challenge testing (HCT) to determine whether supplemental in-flight oxygen is required, but it is not universally available. Objectives: (1) To validate a previously published pre-flight assessment algorithm in predicting outcomes of HCT in ILD. (2) Compare the sensitivity and specificity of the original algorithm to an amended version published in the BTS clinical statement on air travel. Design: Single centre, cohort study. Methods: A single-centre retrospective cohort analysis of ILD patients attending for HCT between March 2017 and April 2023. Results: A total of 126 patients with a diagnosis of ILD underwent HCT. Median forced vital capacity 75.0% predicted (interquartile range (IQR) 24.8) and transfer factor for carbon monoxide 45.8% predicted (IQR 18.6). Diagnosis of idiopathic pulmonary fibrosis in 50.8% (n = 64). A total of 18 individuals became hypoxic during the test (a fall of PaO2 to

AB - Background: The British Thoracic Society (BTS) currently recommends pre-flight clinical assessment of all symptomatic patients with interstitial lung disease (ILD). This may include hypoxic challenge testing (HCT) to determine whether supplemental in-flight oxygen is required, but it is not universally available. Objectives: (1) To validate a previously published pre-flight assessment algorithm in predicting outcomes of HCT in ILD. (2) Compare the sensitivity and specificity of the original algorithm to an amended version published in the BTS clinical statement on air travel. Design: Single centre, cohort study. Methods: A single-centre retrospective cohort analysis of ILD patients attending for HCT between March 2017 and April 2023. Results: A total of 126 patients with a diagnosis of ILD underwent HCT. Median forced vital capacity 75.0% predicted (interquartile range (IQR) 24.8) and transfer factor for carbon monoxide 45.8% predicted (IQR 18.6). Diagnosis of idiopathic pulmonary fibrosis in 50.8% (n = 64). A total of 18 individuals became hypoxic during the test (a fall of PaO2 to

KW - idiopathic pulmonary fibrosis

KW - interstitial lung disease

KW - air travel

KW - hypoxic challenge test

KW - pulmonary fibrosis

U2 - 10.1177/17534666261431183

DO - 10.1177/17534666261431183

M3 - Article (Academic Journal)

C2 - 41833361

SN - 1753-4666

VL - 20

JO - Therapeutic Advances in Respiratory Disease

JF - Therapeutic Advances in Respiratory Disease

M1 - 17534666261431183

ER -

Validation of pre-flight algorithms in predicting hypoxic challenge testing (HCT) outcomes in interstitial lung disease (ILD)

Abstract

Bibliographical note

Research Groups and Themes

Keywords

Access to Document

Handle.net

Fingerprint

Cite this