BETWEEN-PERSON AND WITHIN-PERSON VARIABILITY IN VITAMIN D, PHYSICAL ACTIVITY, PAIN, AND FALLS RISK
Bibliographic record
Abstract
Aims: To describe the associations between falls risk, and between-person and within-person variability in 25-hydroxyvitamin D (25OHD), physical activity (PA), knee pain and dysfunction in community-dwelling older people. Methods: Data for 1099 participants (51% women; mean age 63 ± 7.5 years) studied at baseline, 2.5, 5, and 10 years were analysed. Falls risk (Z-score) was measured using the validated physiological Profile Assessment. Knee pain and dysfunction were assessed using the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC). Moderate and vigorous PA (MVPA) was measured using accelerometer. Mixed effect regression analysis was used to model the association between falls risk and between-person and within-person variability in PA, 25OHD and WOMAC score. Results: Between-person effect showed that 10-year average falls risk was lower in participants who had a higher 10-year average 25OHD (β= –0.006 per nmol/l, 95% CI: –0.009, –0.004, P<0.001), MVPA (β= –0.07 per 10 minutes, 95% CI: –0.01, –0.04, P<0.001) and lower mean WOMAC score (β=0.005 per-unit score, 95% CI: 0.004, 0.007, P<0.001). Within-person effect showed that a higher falls risk was associated with higher than average WOMAC score (β=0.003 per-unit score, 95% CI: 0.001, 0.005, P=0.003) and lower than average MVPA (β= –0.12 per 10 minutes, 95% CI: –0.17, –0.08, P<0.001) but not 25OHD. Conclusion: Having knee pain and dysfunction above an individual’s average increases the risk of falling, whereas, increasing one’s own MVPA level further reduces their risk of falling. The presence of between-person but not within-person associations for 25OHD suggests the former may be confounded by other factors.
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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 | 0.005 | 0.007 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| 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".