Effect of age on ISTH-BAT scores and low VWF diagnosis in the Zimmerman Program
Bibliographic record
Abstract
ABSTRACT: An essential component of low von Willebrand factor (VWF)/type 1 von Willebrand disease (VWD) diagnosis is to identify patients with an increased bleeding phenotype, as most individuals with VWF levels in the 30 to 50 IU/dL range do not bleed. The International Society on Thrombosis and Haemostasis-bleeding assessment tool (ISTH-BAT), widely used for assessing bleeding severity, has recently been shown to be age dependent. Although age may also influence ISTH-BAT scores in individuals with VWF levels between 30 and 50 IU/dL, and subsequently affect low VWF diagnosis, this relationship has not been investigated. Therefore, we analyzed 325 participants from the Zimmerman Program, of whom 220 (67.7%) had abnormal ISTH-BAT scores, whereas 105 (32.3%) had normal scores. Our analysis demonstrates that age critically influences the likelihood of attaining an abnormal ISTH-BAT score and, consequently, being registered with a formal diagnosis of low VWF/type 1 VWD. For example, children first assessed at ≥10 years, are twice as likely to have an abnormal ISTH-BAT compared with those first investigated at <10 years (P < .001). In addition, the prevalence of abnormal ISTH-BAT scores was significantly higher in women aged ≥44 years (91.8%) compared with women aged 18 to 28 years (66.7%; P = .004). Finally, we demonstrate that the change in abnormal ISTH-BAT threshold at the age of 18 years critically affects low VWF diagnosis, owing to lower rates of abnormal scores in young adults (P = .006). In conclusion, we demonstrate that the likelihood of a low VWF/type 1 VWD diagnosis is influenced by the age at which ISTH-BAT is first assessed in individuals with mild-to-moderately reduced VWF levels.
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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 | 0.000 | 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".