Adherence to Guidelines for Surveillance Colonoscopy in Patients with Ulcerative Colitis at a Canadian Quaternary Care Hospital
Bibliographic record
Abstract
BACKGROUND: Patients with ulcerative colitis (UC) are at high risk of colonic dysplasia. Therefore, surveillance colonoscopy to detect early dysplasia has been endorsed by many professional organizations. OBJECTIVES: To determine whether gastroenterologists at Hamilton Health Sciences (Hamilton, Ontario) adhere to recommendations for UC surveillance issued by the Canadian Association of Gastroenterology and to retrospectively assess the incidence and type of dysplasia found and the subsequent outcome of patients with dysplasia (ie, colorectal cancer [CRC], colectomy, dysplasia recurrence). METHODS: A retrospective chart review of all patients with UC undergoing colonoscopy screening at Hamilton Health Sciences from January 1980 to January 2005, was performed. Patients were classified by the extent of colonic disease: limited left-sided colitis (LSC), pancolitis and any disease extent with concurrent primary sclerosing cholangitis. RESULTS: A total of 141 patients fulfilled eligibility criteria. They underwent 921 endoscopies, including 453 for surveillance, which were performed by 20 endoscopists. Overall, screening was performed on 90% of patients, and surveillance at the appropriate time in 74%. There was a statistically significant increase in the mean number of biopsies per colonoscopy after the guidelines were published (P<0.01 for all categories). Colonic dysplasia was detected in 24 of 141 patients (17.0%), with 17 of 24 (70.8%) found at surveillance. Two patients (8.3%) had CRC successfully treated. The average age of patients with dysplasia was 56.1 years, with a mean disease duration of 10.9 years in LSC versus 11.8 years in pancolitis (P not significant). Colectomy was not recommended for any patient with flat dysplasia. No patients progressed to high-grade dysplasia or CRC. Patients with pancolitis had a higher incidence of neoplasia (21% [18 of 86]) than patients with LSC (12% [6 of 49]; P=0.24). Forty-one patients (29.5%) had at least one hyperplastic or inflammatory polyp. CONCLUSIONS: For the majority of patients who underwent surveillance colonoscopies, their procedures were performed within the recommended time intervals, and biopsy compliance has improved. Dysplasia tended to arise after approximately 10 years of disease duration and in middle age, with flat dysplasia being rare. Interventions resulted in no dysplasia progressing to CRC, implying successful prevention.
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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 | 0.001 | 0.010 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| 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".