Concordance between FVC and FEV <sub>6</sub> for identifying chronic airflow obstruction and spirometric restriction in the Burden of Obstructive Lung Disease (BOLD) study
Bibliographic record
Abstract
Introduction We investigated whether the forced expiratory volume in 6 s (FEV 6 ) can be used as a surrogate for the forced vital capacity (FVC). Methods The Burden of Obstructive Lung Disease is a multinational cohort study. At baseline, data were collected from adults, aged 40 years or older, from 41 sites across 34 countries. Participants from 18 sites were followed-up after a median of 8.3 years. Participants who completed the study core questionnaire and had acceptable post-bronchodilator spirometry were included. We performed receiver operating characteristic analyses to measure the ability of FEV 1 /FEV 6 less than the lower limit of normal (LLN) to correctly classify FEV 1 /FVC less than the LLN, and FEV 6 less than the LLN to correctly classify FVC less than the LLN. We used multilevel regression analyses to assess the association of discordant measurements with respiratory symptoms, quality of life and lung function decline. Results At baseline, 28 604 participants were included. 53% were female (15 060). 10% (2876) had chronic airflow obstruction for FEV 1 /FVC, compared with 9% (2704) for FEV 1 /FEV 6 . 37% (10 637) had spirometric restriction for FVC, compared with 35% (9978) for FEV 6 . The FEV 1 /FEV 6 had excellent accuracy in identifying FEV 1 /FVC less than the LLN (area under the curve (AUC): 0.90, 95% CI, 0.89 to 0.91, κ coefficient 0.82). The FEV 6 also had excellent agreement in identifying FVC less than the LLN (AUC: 0.95, 95% CI, 0.94 to 0.95, κ coefficient 0.90). Discordant reductions in FEV 1 /FEV 6 (1%, 345) and FEV 6 (1%, 309) were associated with greater odds of having respiratory symptoms and a lower physical quality of life. 3870 participants were followed up. Those with discordant reductions in FEV 1 /FEV 6 and FEV 6 were more likely to have chronic airflow obstruction and spirometric restriction at follow-up. Conclusions There is strong agreement between the FVC and FEV 6 in the identification of chronic airflow obstruction and spirometric restriction.
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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 | 0.006 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.002 | 0.004 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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".