Phenotyping Exertional Breathlessness Using Cardiopulmonary Cycle Exercise Testing in People With Chronic Airflow Limitation
Bibliographic record
Abstract
Exertional breathlessness is a cardinal symptom of people with chronic airflow limitation (CAL) and can be evaluated using cardiopulmonary exercise testing (CPET). Does abnormally high exertional breathlessness in relation to the rate of oxygen uptake (V’O 2 ) and minute ventilation (V’ E ) indicate different underlying pathophysiological mechanisms and clinical characteristics in people with CAL? Analysis of people aged ≥40 years with CAL (post-bronchodilator FEV 1 /FVC upper limit of normal) by V’O 2 alone, abnormal by both V’O 2 and V’ E (B-V’O 2 +V’ E ), or normal by both V’O 2 and V’ E (B-normal). Exercise physiological responses and clinical characteristics were compared between groups. We included 325 people (44% women) with CAL (FEV 1 75.4±[standard deviation] 17.5%predicted). Compared with the B-normal group (n=237[73%]), the B-V’O 2 group (n=29 [9%]) had lower pulmonary diffusing capacity and greater exercise ventilatory inefficiency, whereas the B-V’O 2 +V’ E group (n=50[15%]) had even worse lung function, dynamic critical inspiratory constraints, and exertional breathlessness along with greater symptom burden in daily life, lower physical activity, and worse health status. Exertional breathlessness phenotyped in relation to V’O 2 and V’ E using normative reference equations enable multivariable analyses of underlying symptom mechanisms and associated clinical characteristics.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 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".