Risk of Upper Gastrointestinal Hemorrhage in Warfarin Users Treated With Nonselective NSAIDs or COX-2 Inhibitors
Bibliographic record
Abstract
BACKGROUND: Little is known about the risk of upper gastrointestinal (GI) hemorrhage during the concomitant use of warfarin and selective cyclooxygenase (COX)-2 inhibitors. We examined the association between the concomitant use of warfarin and nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) or selective COX-2 inhibitors in older adults hospitalized for upper GI hemorrhage. METHODS: This nested case-control analysis of multiple linked health care databases conducted over 1 year identified a cohort of patients in Ontario, Canada, who were older than 66 years and continuously prescribed warfarin. Case patients were those admitted to the hospital with upper GI hemorrhage while taking warfarin. We compared their prescription records prior to hospitalization with those of age- and sex-matched controls who were also receiving warfarin (the control-case ratio was 4:1). Odds ratios (ORs) for the risk of hospitalization for upper GI hemorrhage while concomitantly using warfarin and celecoxib, rofecoxib, or nonselective NSAIDs were determined. RESULTS: During the study period, we identified 98 821 elderly patients continuously receiving warfarin. Of those, 361 (0.3%) were admitted to the hospital with upper GI hemorrhage. After adjusting for other potential confounders, case patients were significantly more likely to be also taking nonselective NSAIDs (OR, 1.9; 95% confidence interval [CI], 1.4-3.7), celecoxib (OR, 1.7; 95% CI, 1.2-3.6), or rofecoxib (OR, 2.4; 95% CI, 1.7-3.6) prior to hospitalization relative to controls. CONCLUSIONS: Patients taking warfarin concomitantly with selective COX-2 inhibitors have an increased risk of hospitalization for upper GI hemorrhage. The risk appears similar to that of patients simultaneously taking warfarin and nonselective NSAIDs.
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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 | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".