The role of early colonoscopy in patients presenting with acute lower gastrointestinal bleeding: a systematic review and meta-analysis
Bibliographic record
Abstract
OBJECTIVE: The use of early colonoscopy in the management of acute lower gastrointestinal bleeding (LGIB) is controversial, with disparate evidence. We aim to formally characterize the utility of early colonoscopy (within 24 h) in managing acute LGIB. DESIGN: A systematic literature search to August 2016 identified fully published and abstracts of randomized controlled trials (RCTs) and observational studies assessing early colonoscopy in acute LGIB. Single-arm studies were also included to define incidence. Primary outcomes were overall rebleeding rates and time to rebleeding. Secondary outcomes included mortality, surgery, length of stay (LOS), definite cause of bleeding and adverse events (AEs). Odds ratios (OR) and weighted mean differences (WMD) were calculated. RESULTS: Of 897 citations, 10 single-arm, 9 observational studies, and 2 RCTS were included (25,781 patients). Rebleeding was no different between patients undergoing early colonoscopy and controls (seven studies, OR = 0.89, 95% CI 0.49-1.62), or RCT data only (OR = 1.00, 95% CI 0.52-1.62). Early colonoscopy detected more definitive sources of bleeding (OR = 4.12, 95% CI 2.00-8.49), and was associated with shorter LOS colonoscopy (WMD = -1.52, 95% CI -2.54 to -0.50 days). No other differences were noted between early and late colonoscopy. AEs occurred in 4.0%, (95% CI 2.9%; 5.4%) of early colonoscopies. Included studies were of low quality, with significant heterogeneity for some outcomes. CONCLUSION: Early colonoscopy in acute LGIB does not decrease rebleeding, mortality or need for surgery, but is associated with increased detection of definitive sources of bleeding, shorter LOS, with low complication incidence. However, the quality of evidence is low, highlighting the need for additional high-level studies.
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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 | 0.031 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.018 | 0.035 |
| Bibliometrics | 0.007 | 0.007 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.002 |
| Open science | 0.002 | 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".