A165 DOES APPENDECTOMY PREVENT THE SUBSEQUENT DEVELOPMENT OF ULCERATIVE COLITIS?: A SYSTEMATIC REVIEW AND META-ANALYSIS
Bibliographic record
Abstract
Abstract Background Ulcerative colitis (UC) is a disease with a heavy burden of morbidity, for which we do not fully understand its etiology. Researchers have anecdotally observed a preventative effect of appendectomy on the risk of developing UC, with multiple studies exploring this relationship. Aims We aimed to complete a systematic review and meta-analysis, the largest of its kind, to determine with more certainty the effect of appendectomy on the subsequent development of UC. Methods A literature search and a review of reference lists of previously published articles was done to identify studies exploring the association between appendectomy and the subsequent development of UC. Our primary endpoint was the diagnosis of UC. Other variables of interest were geographical region, publication date, and age at time of appendectomy. Odds ratios with 95% confidence intervals (CI) are reported. Results Fifty-one studies (49 case-controls studies and 2 cohort studies) were included with a total of 1,270,332 participants. The pooled OR showed that appendectomy decreases the odds of developing UC (Figure 1; OR 0.37, 95% CI, 0.29–0.46, I2 = 89%). A similar pattern was seen for individuals who received an appendectomy before the age of 20 (Figure 2; OR 0.35, 95% CI, 0.21–0.61, I2 0%). The protective effect was seen again when including only high quality methodological studies with Newcastle-Ottawa scale ≥ 7 (Figure 3; OR 0.47, 95% CI, 0.34–0.65, I2 56%). Conclusions Appendectomy may be protective against subsequent development of UC. Future research should focus on the physiological explanation behind this association, and the practicality of using appendectomy as a primary prevention measure in patients at high-risk of developing ulcerative colitis. Funding Agencies None
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.007 | 0.003 |
| Bibliometrics | 0.000 | 0.000 |
| 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) | 0.000 | 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 teacher head, 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".