The effects of leg crossing and applied tension on blood donor return
Bibliographic record
Abstract
BACKGROUND AND OBJECTIVES: Repeated isometric muscle tension (applied tension) during blood donation reduces vasovagal symptoms in many donors. Experiencing vasovagal symptoms has been found to reduce blood donor return. However, does practicing applied tension improve blood donor return? Follow-up results from a randomized controlled trial are presented. METHODS: Data were collected in mobile clinics held in several colleges and universities. During the baseline donation, participants either (1) practiced 'standard' applied tension consisting of repeated 5 s cycles of whole-body isometric muscle tension in the donation chair (N = 133), (2) practiced tension with legs crossed (N = 131), or (3) gave blood as usual (N = 140). Subsequent blood donations in the following 2 years were determined. RESULTS: Applied tension had no effect on immediate (at the end of the baseline blood donation) rating of intention to give blood or the dichotomous measure of whether or not the participant gave blood again in the following 2 years. However, men asked to practice applied tension with legs crossed gave approximately one unit more during the follow-up period compared with men in the control group (F1,106 = 5·32, P = 0·023). This was associated significantly with adherence - men assigned to the applied tension with legs crossed condition who did not practice as instructed were no more likely to return than controls. CONCLUSION: The results provide modest support for the idea that applied tension may increase subsequent blood donation though the results were limited to men who practiced the technique as instructed.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".