Abnormal breathlessness during cardiopulmonary exercise testing - validation in people with chronic airflow limitation
Bibliographic record
Abstract
ABSTRACT Background Exertional breathlessness is the cardinal symptom in cardiorespiratory disease. We aimed to validate recently developed normative reference equations to evaluate breathlessness abnormality during cardiopulmonary exercise testing (CPET) in people with chronic airflow limitation. Methods Analysis of people aged ≥40 years with chronic airflow limitation undergoing CPET in the Canadian Cohort Obstructive Lung Disease (CanCOLD) study. Breathlessness intensity ratings (Borg 0-10 category ratio scale [CR10]) were evaluated in relation to power output (W), rate of oxygen uptake (V’O 2 ), and minute ventilation (V’ E ) at peak exercise using normative reference equations as: 1) probability of breathlessness normality, defined as the predicted probability of the Borg CR10 rating among healthy references, with lower probability reflecting more severe breathlessness; and 2) presence of abnormal breathlessness, defined as a Borg CR10 intensity rating above the upper limit of normal (ULN). Validity of breathlessness severity (lower probability of normality) and abnormality (>ULN) was evaluated as correlations with relevant participant-reported and physiologic outcomes. Results We included 330 participants (44% women): mean±SD age 64±10 years (range 40– 89), FEV 1 /FVC 57.3±8.2%, FEV 1 75.6±17.9%predicted. Relative to peak W, V’O 2 and V’ E , abnormal breathlessness was present in 22.7%, 21.5%, and 15.2% of participants, respectively. For all equations, people with abnormal breathlessness had worse lung function, exercise capacity, self-reported symptom burden, physical activity, health-related quality of life, and physiological abnormalities during CPET. Conclusion Evaluation of breathlessness abnormality using CPET normative reference equations was valid in people with chronic airflow limitation.
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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 | 0.004 | 0.009 |
| 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 | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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".