VENUS - A Study To Validate Centrally Adjudicated Venous Ultrasound Against Venography after Major Orthopaedic Surgery.
Bibliographic record
Abstract
Abstract Mandatory, bilateral, centrally adjudicated venography is currently required to assess the incidence of deep vein thrombosis (DVT) in confirmatory trials of new antithrombotic agents. Non-invasive and less cumbersome methods would be welcomed by both patients and investigators. Centrally adjudicated complete compression ultrasound (CCUS) of all leg veins could become an alternative to venography. Despite the fact that no formal validation of venography has ever been performed, CCUS will have to be externally validated against this ’gold standard’ to gain general acceptance and regulatory approval. A substudy of two recent phase IIb trials of a novel, oral anticoagulant for the prevention of venous thromboembolism in patients undergoing elective hip or knee arthroplasty was undertaken to validate CCUS against venography. The studies had similar designs and methodology, and were designed to allow the pooling of data. Mandatory bilateral venography was performed 7±2 days after surgery; CCUS was performed later the same day, with the sonographers blinded to the venography result. All sonographers were required to have completed a training course, and to have obtained personal certification for the standardized examination and documentation procedure. Venograms and CCUS videos were adjudicated centrally by two independent readers at separate locations; discrepancies were resolved by consensus reading. From the 1347 patients participating in the two trials, 870 matching pairs of evaluable venograms and CCUS videos were obtained. Observed prevalences of any DVT, including muscle vein thrombosis, were 19.1% with venography, and 13.0% with CCUS. Sensitivity and specificity values [with 95% confidence intervals (95% CI)] for detecting DVT with CCUS are shown in the table. Although false positives did not severely impair specificity, the small number of true positives detected by CCUS resulted in remarkably low sensitivity, in particular for proximal DVT. Based on these external validation figures, centrally adjudicated CCUS is not a viable technique to replace venography for the screening of DVT early after major orthopaedic surgery in confirmatory trials of novel antithrombotic agents. DVT Sensitivity [% (95% CI)] Specificity [% (95% CI)] Any 27.4 (21.2, 33.6) 95.8 (94.8, 96.8) Proximal 13.0 (−0.7, 26.8) 99.2 (98.9, 99.7) Distal 25.9 (19.7, 32.1) 96.2 (95.3, 97.2)
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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 | 0.024 | 0.035 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".