Mortality and diagnostic practice variation in interstitial lung disease admissions: insights from a multicentre UK cohort study
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Background. Interstitial lung diseases (ILD) are a heterogenous group of often progressive,
unpredictable diseases. They frequently result in hospitalisations secondary to respiratory
decompensation, termed ILD-related admissions. A proportion are due to acute exacerbations
(AEILD). All are associated with high mortality but poorly characterised in real-world populations.
Aim. To evaluate mortality outcomes and associated risk factors following ILD-related hospital
admissions, including AEILD.
Methods. We conducted a multicentre retrospective cohort study of primary ICD10 coded
admissions for ILD between 01.01.2017 and 31.12.2019 across 11 NHS hospitals in the North
West of England. AEILD events were classified using clinical criteria: <30-day respiratory
deterioration not secondary to cardiac failure, pulmonary embolism or pneumothorax. The AEILD
sub-group was divided into those with CT confirmation (definite AEILD) and without CT
confirmation (suspected AEILD). Primary outcome was time from admission to death. Statistical
analyses included Kaplan-Meier and multivariate proportional hazards modelling.
Results. Of 938 ILD-related admissions, 54.5% met study AEILD criteria. Overall 90-day all-cause
mortality was 40.2%. For the AEILD cohort, 90-day all-cause mortality was 47.6%. Median survival
of the AEILD cohort was 107 days (95% CI 87.0 – 141.0 days) and other ILD-related admission
cohort 241.0 days (95% CI 208.0 – 308.0 days), with a statistically significant difference in survival
(p <0.0001). 37.6% (192/511) of AEILD events had CT confirmation. Within the AEILD sub-group,
median survival was higher in the CT group (144 days vs. 100 days, p = 0.027). AEILD was
independently associated with mortality in a multivariate model. Pre-admission oxygen, age and
neutrophilia were associated with mortality in both ILD-admission and AEILD 90-day all-cause
mortality models. 13.9% of admissions had documented palliative care input.
Conclusion. Mortality associated with ILD-related admissions is high, with AEILD events
independently associated with mortality. Findings highlight the need for improved education,
access to palliative care and targeted AEILD research.
unpredictable diseases. They frequently result in hospitalisations secondary to respiratory
decompensation, termed ILD-related admissions. A proportion are due to acute exacerbations
(AEILD). All are associated with high mortality but poorly characterised in real-world populations.
Aim. To evaluate mortality outcomes and associated risk factors following ILD-related hospital
admissions, including AEILD.
Methods. We conducted a multicentre retrospective cohort study of primary ICD10 coded
admissions for ILD between 01.01.2017 and 31.12.2019 across 11 NHS hospitals in the North
West of England. AEILD events were classified using clinical criteria: <30-day respiratory
deterioration not secondary to cardiac failure, pulmonary embolism or pneumothorax. The AEILD
sub-group was divided into those with CT confirmation (definite AEILD) and without CT
confirmation (suspected AEILD). Primary outcome was time from admission to death. Statistical
analyses included Kaplan-Meier and multivariate proportional hazards modelling.
Results. Of 938 ILD-related admissions, 54.5% met study AEILD criteria. Overall 90-day all-cause
mortality was 40.2%. For the AEILD cohort, 90-day all-cause mortality was 47.6%. Median survival
of the AEILD cohort was 107 days (95% CI 87.0 – 141.0 days) and other ILD-related admission
cohort 241.0 days (95% CI 208.0 – 308.0 days), with a statistically significant difference in survival
(p <0.0001). 37.6% (192/511) of AEILD events had CT confirmation. Within the AEILD sub-group,
median survival was higher in the CT group (144 days vs. 100 days, p = 0.027). AEILD was
independently associated with mortality in a multivariate model. Pre-admission oxygen, age and
neutrophilia were associated with mortality in both ILD-admission and AEILD 90-day all-cause
mortality models. 13.9% of admissions had documented palliative care input.
Conclusion. Mortality associated with ILD-related admissions is high, with AEILD events
independently associated with mortality. Findings highlight the need for improved education,
access to palliative care and targeted AEILD research.
Date Acceptance
2026-03-04
Citation
BMJ Open Respiratory Research
ISSN
2052-4439
Publisher
BMJ Publishing Group
Journal / Book Title
BMJ Open Respiratory Research
Copyright Statement
Copyright This paper is embargoed until publication. Once published the Version of Record (VoR) will be available on immediate open access.
License URL
Publication Status
Accepted