Utility of diaphragm dome height as a marker of operational lung volume changes, disease burden and exacerbations in patients with mild-to-moderate COPD: an observational study within the CanCOLD cohort
Bibliographic record
Abstract
Background Dynamic hyperinflation is central to dyspnoea, exercise limitation and exacerbations in COPD. While studied previously in moderate-to-severe COPD, the relevance of diaphragm dome height (DDH) on clinically important outcomes has been under-investigated in mild-to-moderate COPD. Methods Canadian Cohort Obstructive Lung Disease (CanCOLD) participants with spirometry-confirmed COPD, symptom-limited incremental cardiopulmonary exercise testing and computed tomography image data were included. Base-to-apex left DDH (LDDH) and right DDH (RDDH) were automatically segmented, with increased height implying less flattening and thus less hyperinflation. Dynamic hyperinflation was defined as ≥150 mL reduction in inspiratory capacity (IC) from rest to peak exercise. Cross-sectional linear regression models were fitted between LDDH and RDDH (predictor variables) with peak IC (IC peak ), peak workload ( W peak ), forced expiratory volume in 1 s (FEV 1 ) and COPD Assessment Test (CAT) score (outcome variables), and in longitudinal (Anderson–Gill) models with “symptom-based” and “event-based” exacerbations. Results are reported as parameter estimates or hazard ratios (HRs) with 95% confidence intervals per interquartile range dome height increment. Results Amongst 304 participants (mean± sd age 64.7±10.3 years, 41.8% female, 44.4% with mild COPD), each LDDH and RDDH increment, respectively, was associated with IC peak (0.21 (95% CI 0.13–0.29) L and 0.13 (95% CI 0.07–0.19) L), W peak (9.54 (95% CI 5.03–14.04) W and 6.04 (95% CI 2.45–9.62) W), FEV 1 (0.17 (95% CI 0.10–0.25) L and 0.08 (95% CI 0.02–0.14) L) and CAT score (−1.36 (95% CI −2.39– −0.33) and −0.82 (95% CI −1.63–0.00)). LDDH alone was associated with both symptom-based (HR 0.82 (95% CI 0.74–0.91)) and event-based (HR 0.83 (95% CI 0.73–0.95)) exacerbations. Of 167 out of 304 participants with confirmed dynamic hyperinflation (ΔIC −0.47±0.25 L), LDDH alone was associated with all outcomes (IC peak , W peak , FEV 1 , CAT and symptom-based/event-based exacerbations). Conclusions LDDH appears to be a clinically important marker for operational lung volume changes, lung function, exercise performance, disease burden and exacerbations in mild-to-moderate COPD.
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| 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 teacher head, 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".