Prevalence and burden of COPD misclassification in the Canadian Longitudinal Study on Aging (CLSA)
Bibliographic record
Abstract
INTRODUCTION: To examine the prevalence of chronic obstructive pulmonary disease (COPD) misclassification and the associated burden of symptoms, healthcare utilisation and physical performance status in the Canadian general population. This information is presently lacking from large population-based studies with high-quality spirometry data that can be generalised to the general population. METHODS: The prevalence of self-reported physician-diagnosed COPD and the concordance with spirometry airflow obstruction (AO) were assessed in a cross-sectional cohort of Canadian older adults. The associations between confirmed COPD, under-diagnosis and over-diagnosis with self-reported respiratory symptoms, healthcare utilisation and physical performance (timed up and go, handgrip strength and 4 metres walk test) were assessed, adjusting for baseline characteristics using multivariable linear and logistic models. RESULTS: A total of 21 242 participants (mean age 64 (SD 10) years; 42% men) with high quality spirometry were included. Physician-diagnosed COPD was reported in (n=973) 5% of the participants. Only (n=217) 1% of the entire cohort had confirmed COPD supported by spirometry AO. Discordance between self-reported COPD and spirometry findings was observed in (n=1565) 8%: with 4% representing under-diagnosis cases (no self-reported COPD but AO) and 4% representing over-diagnosis cases (self-reported COPD but no AO). Compared with normals (no self-reported COPD and normal spirometry), those with confirmed, under-diagnosed or over-diagnosed COPD showed higher risks for respiratory symptoms (adjusted OR (aOR) 2.1 (95% CI: 1.6 to 2.7); aOR 1.8 (95% CI: 1.6 to 2.1]; aOR 1.6 (95% CI: 1.4 to 1.9)); healthcare utilisation in the prior 12 months (β coefficient 0.8 (95% CI: 0.2 to 2.6); β 0.9 (95% CI: 0.5 to 1.5); β 1.6 (95% CI: 0.7 to 4.0)). Mood disorders were higher in confirmed and over-diagnosed COPD (aOR 1.7 (95% CI: 1.3 to 2.4); 1.7 (95% CI: 1.4 to 2.0), respectively). Physical performance was lower for COPD groups. CONCLUSIONS: The prevalence of COPD misclassification is high in the general population of older adults. These were associated with significantly high burden of respiratory symptoms, healthcare utilisation and low physical performance compared with the general population with normal spirometry and no self-reported COPD. These findings highlight the high burden of COPD misclassification, which may be substantially reduced with greater accessibility to spirometry measurements in the community.
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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 | 0.006 | 0.010 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.003 | 0.005 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".