Urgent Versus Standard Colonoscopy for Management of Acute Lower Gastrointestinal Bleeding
Bibliographic record
Abstract
BACKGROUND: Acute lower gastrointestinal bleeding (LGIB) is a common indication for hospitalization. However, the optimum timing of colonoscopy following patient presentation remains unclear. This systematic review and meta-analysis aims to evaluate the effect of urgent versus standard colonoscopy timing on management of acute LGIB. MATERIALS AND METHODS: Medline, EMBASE, CENTRAL, and PubMed were searched up to January 2020. Randomized controlled trials were eligible for inclusion if they compared patients with hematochezia receiving urgent (<24 h) versus standard (>24 h) colonoscopy. Nonrandomized observational studies were also included based on the same criteria for additional analysis. Pooled estimates were calculated using random effects meta-analyses and heterogeneity was quantified using the inconsistency statistic. Certainty of evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluation (GRADE). RESULTS: Of 3782 potentially relevant studies, 4 randomized controlled trials involving 463 patients met inclusion criteria. Urgent colonoscopy did not differ significantly to standard timing with respect to length of stay (LOS), units of blood transfused, rate of additional intervention required, or mortality. Colonoscopy-related outcomes such as patient complications, rebleeding rates, and diagnosis of bleeding source did not differ between groups. However, meta-analysis including nonrandomized studies (9 studies, n=111,950) revealed a significantly higher rate of mortality and complications requiring surgery in the standard group and shorter LOS in the urgent group. Overall GRADE certainty of evidence was low in the majority of outcomes. CONCLUSIONS: Timing of colonoscopy in acute LGIB may not significantly affect patient outcomes. Timing should therefore be decided on a case-by-case basis.
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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 | 0.011 | 0.026 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.009 | 0.015 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| 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".