A67 PERFORMANCE OF COMPUTED TOMOGRAPHY IN MANITOBA
Bibliographic record
Abstract
Colorectal cancer (CRC) is the third most common cancer in the world and the second most common cause of cancer related deaths in North America. The incidence of CRC has been declining in the North America at least partly due to implementation of CRC screening aimed at detecting premalignant polyps from which CRC arise. Various screening tests are currently available including Fecal Occult Blood Test, Flexible Sigmoidoscopy, Computed Tomography Colonography (CTC) and Optical Colonoscopy. CTC is a non-invasive modality which has become highly reliable in detecting CTC and large colon polyps. The US Preventive Services Task Force (USPTF) recently added CTC to the list of acceptable screening modalities. In Manitoba, CTC is performed only in the Winnipeg Regional Health Authority (WHRA). It has been performed since 2009. Assess performance of CTC in usual clinical practice in Canada: including indications for CTC, specialty of the ordering physicians, proportion of procedures that detect polyps, and colonic and extra-colonic findings and recommended follow up. Retrospective review of CTCs reports within the WHRA. Follow-up imaging reports were also reviewed. Descriptive statistics are used to describe the data. In the year 2012, 195 CTC were performed. The majority (54%) were ordered by gastroenterologists, followed by surgeons (27%), family physicians (13%) and a few by general internists (0.05%). Incomplete colonoscopies were the major reason for ordering CTC (70%), while only (24%) were used as a primary screening modality. 17% of the CTCs reported colonic polyps and 52% extra-colonic lesions, of which 37% were recommended follow-up radiological imaging which occurred in less than half of those for whom it was recommended. CTC is primarily being used in Manitoba by gastroenterologists for assessment of incomplete colonoscopies. A high proportion of CTCs in usual clinical practice report extra-colonic findings, a follow-up of which is recommended in a large portion. Reasons for lack of recommended radiological follow-up need to be studied and measures developed to ensure completion of the recommended follow-up. The data for other years is being reviewed and will also be presented. 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 | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.005 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.017 | 0.004 |
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".