Exercise ventilatory inefficiency in mild to end-stage COPD
Bibliographic record
Abstract
Ventilatory inefficiency during exercise is a key pathophysiological feature of chronic obstructive pulmonary disease. Currently, it is unknown how this physiological marker relates to clinically relevant outcomes as resting ventilatory impairment progresses across disease stages. Slope and intercept of the linear region of the ventilation-carbon dioxide output relationship and the ratio between these variables, at the lowest point (nadir), were contrasted in 316 patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages 1-4 (forced expiratory volume in 1 s, ranging from 148% pred to 12% pred) and 69 aged- and gender-matched controls, Compared to controls, slope and intercept were higher in GOLD stages 1 and 2, leading to higher nadirs (p<0.05). Despite even larger intercepts in GOLD stages 3 and 4, slopes diminished as disease evolved (from mean±sd 35±6 in GOLD stage 1 to 24±5 in GOLD stage 3, p<0.05). As a result, there were no significant differences in nadirs among patient groups. Higher intercepts, across all stages (p<0.01), and to a lesser extent lower slopes in GOLD stages 2-4 (p<0.05), were related to greater mechanical constraints, worsening pulmonary gas exchange, higher dyspnoea scores, and poorer exercise capacity. Increases in the ventilation intercept best indicate the progression of exercise ventilatory inefficiency across the whole spectrum of chronic obstructive pulmonary disease severity.
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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 | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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 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".