Agreement between core laboratory and study investigators for imaging scores in a thrombectomy trial
Bibliographic record
Abstract
PURPOSE: We aimed to assess the agreement between study investigators and the core laboratory (core lab) of a thrombectomy trial for imaging scores. METHODS: The Alberta Stroke Program Early CT Score (ASPECTS), the European Collaborative Acute Stroke Study (ECASS) hemorrhagic transformation (HT) classification, and the Thrombolysis In Cerebral Infarction (TICI) scores as recorded by study investigators were compared with the core lab scores in order to assess interrater agreement, using Cohen's unweighted and weighted kappa statistics. RESULTS: There were frequent discrepancies between study sites and core lab for all the scores. Agreement for ASPECTS and ECASS HT classification was less than substantial, with disagreement occurring in more than one-third of cases. Agreement was higher on MRI-based scores than on CT, and was improved after dichotomization on both CT and MRI. Agreement for TICI scores was moderate (with disagreement occurring in more than 25% of patients), and went above the substantial level (less than 10% disagreement) after dichotomization (TICI 0/1/2a vs 2b/3). CONCLUSION: Discrepancies between scores assessed by the imaging core lab and those reported by study sites occurred in a significant proportion of patients. Disagreement in the assessment of ASPECTS and day 1 HT scores was more frequent on CT than on MRI. The agreement for the dichotomized TICI score (the trial's primary outcome) was substantial, with less than 10% of disagreement between study sites and core lab. TRIAL REGISTRATION NUMBER: NCT02523261, Post-results.
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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 | 0.001 | 0.001 |
| 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".