P0475 Differential characteristics and predictors of time to colectomy in ulcerative colitis: stratified by medical refractory disease vs. colitis-associated neoplasia
Bibliographic record
Abstract
Abstract Background Colectomy rates for ulcerative colitis (UC) have likely decreased in recent decades due to advancements in therapy, but surgery remains crucial for managing medically refractory disease or UC-associated neoplasia. This study aimed to evaluate the differential characteristics and predictors of early colectomy in UC patients undergoing colectomy for medical refractoriness versus UC-associated neoplasia. Methods We retrospectively reviewed the medical records of 569 UC patients who underwent colectomy at Mount Sinai Hospital, Toronto, between January 2010 to June 2023. Patients with pathologically confirmed UC and surgery due to medical refractoriness (MR) or UC-associated neoplasia were included. We analyzed the clinical characteristics and their impact on time to colectomy from diagnosis using Kaplan-Meier survival analysis and multivariate Cox proportional hazards regression models. Results Among the 394 patients who met the criteria, 57.1% were male, 94.7% had extensive colitis. The median ages at UC diagnosis and colectomy were 25 years (IQR 19–36) and 36 years (IQR 26-49), respectively. Of these, 288 patients (73.1%) underwent colectomy for MR, and 106 patients (26.9%) for UC-associated neoplasia. The median age at colectomy differed between the MR and neoplasia groups (33 years [IQR 24-44] vs 47 years [IQR 35-55], P < 0.001), as did the median UC duration (4 year [IQR 2-8] vs 16 years [IQR 9-21], P < 0.001). The proportion of patients with primary sclerosing cholangitis was higher in the neoplasia group (2.4% vs 20.5%, P < 0.001). The use of systemic steroids (67.7% vs 15.1%, P < 0.001) and biologics or small molecules (68.8% vs 43.4%, P < 0.001) prior to surgery was higher in the MR group. In the MR group, male sex (HR 1.30, 95% CI 1.02-1.66, P = 0.036), never smoking (HR 1.42, 95% CI 1.02-1.98, P = 0.039), and diagnosis age > 40 year (HR 1.58, 95% CI, 1.15-2.16, P = 0.005) were associated with a shorter time to colectomy. In contrast, in the neoplasia group, age at diagnosis > 40 years (HR 0.39, 95% CI 0.25–0.63, P < 0.001) was linked to a longer time to colectomy. Conclusion Significant differences in clinical characteristics were identified between UC patients undergoing colectomy for MR compared with UC-associated neoplasia. Late-onset UC, diagnosed after the age of 40, may be linked to a shorter time to colectomy for medically refractory disease while it seems to have a lower likelihood of early colectomy for neoplasia.
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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 | 0.000 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".