P342 Diagnostic accuracy of rectal bleeding and stool frequency in predicting mucosal healing in patients with ulcerative colitis in the tofacitinib OCTAVE Phase 3 induction studies
Bibliographic record
Abstract
Abstract Background Tofacitinib is an oral, small-molecule JAK inhibitor for the treatment of ulcerative colitis (UC). In patients with UC, associations between endoscopic findings and patient-reported outcomes, such as stool frequency (SF) and rectal bleeding (RB), are not well described. Here, we evaluated the diagnostic accuracy of Mayo SF and RB subscores to predict mucosal healing (MH) in OCTAVE Induction 1 and 2 (NCT01465763; NCT01458951). Methods This post hoc analysis used data from OCTAVE Induction 1 and 2, two identical, randomised, placebo-controlled, 8-week, Phase 3 studies of tofacitinib for the treatment of patients with moderately to severely active UC.1 SF (Mayo subscore 0–3), RB (Mayo subscore 0–3) and endoscopic findings (Mayo endoscopic subscore [ES] 0–3) were assessed at baseline and at Week 8. MH and endoscopic normalisation were defined as an ES of 0 or 1, or an ES of 0, respectively. Based on two-by-two contingency tables, diagnostic test characteristics for SF and RB were evaluated: positive and negative predictive values, sensitivity and specificity. Kappa statistics (chance-corrected measure of agreement) and Pearson correlations (a measure of association) were also calculated. All available data at Week 8 were used. Results A total of 614 and 547 patients received treatment (tofacitinib 15 or 10 mg BID, or placebo) in OCTAVE Induction 1 and 2, respectively. Two-by-two contingency table analyses showed that dichotomised SF (0 vs. ≥1) and RB (0 vs. ≥1) were each or both not good predictors of MH (ES of 0 or 1 vs. ≥2) or endoscopic normalisation (ES 0 vs. ≥1), as ≥1 of the four diagnostic test characteristics was <50% (Table). In OCTAVE Induction 1 and 2, weighted kappa statistics for SF (original metric 0–3) and RB (0–3) vs. ES (0–3) indicated moderate agreement for SF (0.46 and 0.42, respectively), slight agreement for RB (0.19 and 0.15, respectively) and fair agreement for SF and RB (0.40 and 0.34, respectively). Correlations were 0.54 and 0.49 for SF, 0.46 and 0.37 for RB and 0.57 and 0.51 for SF and RB (OCTAVE Induction 1 and 2, respectively), suggesting a modest-to-moderate association. Conclusion In patients with UC treated with tofacitinib or placebo in OCTAVE Induction 1 and 2, SF and RB subscores had slight-to-moderate agreement with ES, but were not predictive of MH or endoscopic normalisation. The presence of blood at Week 8 strongly indicated that patients had endoscopic activity, but the absence of blood was associated with MH in <50% of patients. Further analysis is needed to fully understand the relationship between SF, RB and MH. Reference
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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 | 0.006 | 0.008 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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 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".