A114 SYSTEMATIC REVIEW AND META-ANALYSIS: ENDOSCOPIC AND HISTOLOGIC PLACEBO RATES IN INDUCTION AND MAINTENANCE TRIALS OF ULCERATIVE COLITIS
Bibliographic record
Abstract
Treatment targets in ulcerative colitis (UC) have evolved to include normalization of objective endoscopic and histologic endpoints. Minimizing the endoscopic and histologic placebo response and remission rate is critical for the conduct of efficient randomized controlled trials (RCTs) and development of new treatments, in order to maximize ability to detect differences between active comparator and placebo. To quantify the endoscopic and histologic placebo response and remission rates in induction and maintenance UC RCTs and to identify trial design factors influencing these rates. MEDLINE, EMBASE, and the Cochrane Library were searched from inception through March 1, 2017 for placebo-controlled RCTs of adult patients with UC treated with aminosalicylates, immunosuppressants, corticosteroids, biologics, and oral small molecules. Endoscopic and histologic placebo response and remission rates for induction and maintenance trials were pooled using a random-effects model. Patient- and trial-level covariates were evaluated by constructing stratum-specific rates of placebo response/remission and by random-effects meta-regression analysis. Placebo endoscopic response/remission rates were reported in 45 induction and eight maintenance trials; placebo histologic response/remission rates were reported in nine induction trials. Pooled estimates for placebo induction endoscopic remission, induction endoscopic response, and maintenance endoscopic remission rates were 25% [95 confidence interval (CI): 22–30%], 36% [29–43%], and 20% [16–24%], respectively. The pooled histologic remission rate in induction trials was 16% [10–25%]. Disease severity, disease duration, trial setting, trial phase, class of active comparator, trial follow-up duration, and endoscopic sub-score criterion for trial inclusion were not predictive of placebo endoscopic or histologic remission rates. Pooled placebo endoscopic and histologic response and remission rates vary according to whether trials are designed for induction or maintenance. Potential strategies to further reduce these rates include standardization of histologic scoring as well as the definitions used for response and remission. Figure 1: Forest plot of induction trials reporting placebo endoscopic remission rates, pooled using random-effects model. None
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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 | 0.053 | 0.123 |
| Meta-epidemiology (narrow) | 0.004 | 0.002 |
| Meta-epidemiology (broad) | 0.027 | 0.055 |
| Bibliometrics | 0.012 | 0.013 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.006 | 0.004 |
| Open science | 0.003 | 0.002 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.004 | 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".