Predicting Colonoscopy Duration for Fecal Immunochemical Test Positive Patients Using Information Available at the Time of Referral
Bibliographic record
Abstract
Introduction: Patients undergoing colonoscopy for a positive fecal immunochemical test (FIT) are more likely to have multiple or advanced neoplasia. Therefore, FIT+ colonoscopies may on average take more time than FIT- or average risk screening colonoscopies. Scheduling of FIT+ colonoscopies to an appropriate time slot (i.e. 30 minutes versus 60 minutes) could be facilitated by the identification of factors associated with a long procedure duration. Methods: Withdrawal time and quantitative FIT result (OC-Sensor) were obtained from clinical databases on 3,019 FIT+ (≥75 ng/ml) and 1,384 FIT- patients. All patients were aged 50 - 75 years and asymptomatic and underwent FIT for colorectal cancer screening. All colonoscopies were completed at the Fozani & MacPhail Colon Cancer Screening Centre, a regional publicly-funded colonoscopy screening centre. Withdrawal time was routinely recorded as part of clinical care. Univariate and multivariate logistic regression was used to examine the association between a withdrawal time ≥ 15 minutes, representing a colonoscopy that could not be completed in a typical 30 minute time slot, and factors known at the time of referral (age, gender and quantitative FIT result). From the final model, the area under the receiver operator curve (AROC) and predicted probabilities of a long withdrawal time for different groups were estimated. Results: The FIT- group was 52% male with 18% age 65-75 years. The FIT+ group was 62% males with 34% age 65-75. An advanced adenoma was present in 22.5% of FIT+ and 2.6% of FIT-. The mean withdrawal time for FIT- patients was 9.6 minutes compared with 14.2 minutes for FIT+. Withdrawal time of 15 or more minutes occured in 35% of FIT+ patients compared with only 11% of FIT- patients. In those who were FIT+, gender, age and the quantitative FIT result were each independently associated with withdrawal time (see table). The predicted probability of a withdrawal time of 15 or more minutes was 21% in females aged 50 - 64 with a FIT result of 75 - 99 ng/ml compared with 55% in males over age 64 with a FIT result of 800 ng/ml or greater (AROC 0.6). Conclusion: Male sex, older age and greater amount of occult blood in the stool are each associated with a longer withdrawal time. Therefore, information available at the time of referral predicts the likelihood of a prolonged procedure due to multiple or advanced neoplasia and could be used for optimizing the scheduling of FIT+ patients for colonoscopy.Table 1: Predictors of 15+ Minutes Withdrawal Time
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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 | 0.007 |
| 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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".