Optimizing baseline constant work rate exercise test duration for COPD bronchodilator studies
Bibliographic record
Abstract
Constant work rate (CWR) cycle ergometer testing has been used to evaluate long acting bronchodilator effects (BD) on exercise tolerance. It is recommended that baseline CWR duration be restricted to between 3 and 8 min. We evaluated this recommendation using a database assembled by the COPD Biomarker Qualification Consortium (CBQC). 8 published studies yielded 1349 COPD patient (FEV1=49±14 %pred.) responses studying effects of ~6 wks of BD on CWR duration in tests performed at 75-80% of peak incremental WR. Figure shows a wide range of baseline durations (left); for tests >11 min, duration increase (center) declines and SD (right) increases. Table shows responses for all subjects, those restricted to 3-8 min and to 2-11 min. Also shown is sample size needed in a trial for a cohort with these characteristics and % of subjects requiring re-testing at an altered WR to achieve the desired range. Restricting baseline duration range greatly decreases sample size required. The 2-11 min limit, compared to the 3-8 min limit, yields a much lower fraction of subjects needing repeat tests. A 2-11 min baseline duration limit is proposed for future BD studies.
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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 | 0.024 | 0.024 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".