The Relationship Between Recovery Rate From Exertional Desaturation, Disease Severity and Mortality in Patients With Fibrotic Interstitial Lung Disease
Bibliographic record
Abstract
Abstract RATIONALE: In patients with fibrotic interstitial lung disease (fILD), both oxygen desaturation during exertion and a reduced distance in the six-minute walk test (6MWT) are recognized as independent predictors of mortality. Additionally, experiencing exertional desaturation and a shorter 6MWT distance correlates with increased disease severity, faster progression, and poorer clinical outcomes, including mortality. The recovery rate of peripheral oxygen saturation (SpO₂) after the 6MWT can vary among fILD patients and may change for individuals as their disease worsens or as they develop other co-morbidities. This study aims to explore the relationship between the recovery index (RI) of desaturation after 6MWT and both disease severity and survival in patients with fILD. METHODS: This prospective study enrolled patients with fILD undergoing clinical 6MWT at the University of Calgary ILD program in 2022, with follow-up through October 2024. The 6MWT was administered according to consensus guidelines with continuous pulse oximetry monitoring. Patients with exertional desaturation greater than 3% were included in the analysis. Post-test SpO₂ levels were recorded every 15 seconds for up to 180 seconds or until SpO₂ returned to baseline. RI was calculated using the formula: RI = ([SpO₂(baseline) – SpO₂(end6MWT) + O₂ Flow (LPM)] / [181 – recovery time(s)])[asterisk]100, where a higher RI indicates slower recovery. Baseline characteristics were compared using chi-squared and two-tailed t-tests, while linear regression tested associations between RI and baseline forced vital capacity (FVC) % predicted and diffusion capacity (DLCO) % predicted. Kaplan-Meier plots estimated the unadjusted probability of survival. Cox proportional hazards regression tested the association of RI with risk of death in models adjusted for disease progression. RESULTS: Of 92 patients, 54 had exertional desaturation >3% during the 6MWT. Mean age was 68±9.8 years, 29 (53%) were female, and the most common diagnosis was connective tissue disease-associated ILD in 21 (39%). In unadjusted models, RI was associated with decreased FVC% (β=-0.16, 95%CI -0.2877 to -0.02721; p=0.0184) and DLCO% (β=-0.35, 95%CI -0.4889 to -0.2193; p= 0.0001). Additionally, there was a trend suggesting an association between higher RI and increased dyspnea (BORG-D score, β=1.23, 95%CI -0.2070 to 2.253; p=0.1013). Findings were consistent across all ILD subtypes. CONCLUSION: Prolonged recovery from exertional desaturation following 6MWT is linked to reduced lung function, more symptoms, and a higher risk of mortality in patients with fILD across the various subtypes. The recovery time from exertional desaturation could be an important clinical indicator for evaluating disease severity and predicting outcomes.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".