Increased Use of Acid‐Suppressing Drugs Before the Occurrence of Ischemic Events: A Potential Source of Confounding in Recent Observational Studies
Bibliographic record
Abstract
STUDY OBJECTIVE: To determine if the use of acid-suppressing drugs is increased before the occurrence of ischemic events. DESIGN: Population-based, nested case-control analysis. DATA SOURCE: Administrative databases in Saskatchewan, Canada. PATIENTS: Cases were 1612 patients (aged ≥ 40 yrs) who started a first-ever antihypertensive drug between January 1, 1994, and December 31, 2003, and were hospitalized for a first ischemic heart event of either myocardial infarction (1002 patients) or unstable angina (610 patients); five control patients were matched to each case patient by age, sex, and year of first antihypertensive prescription (8060 controls). MEASUREMENTS AND MAIN RESULTS: Within the case and control groups, we calculated exposure to acid-suppressing therapy, defined as proton pump inhibitors (PPIs) or histamine(2)-receptor antagonists (H(2)RAs), within 90 days leading up to the event. Exposure to acid-suppressing therapy was higher among cases than controls (15.3% [246/1612] vs 10.4% [837/8060], adjusted odds ratio [AOR] 1.26, 95% confidence interval [CI] 1.06-1.49, p<0.009). Exposure to each acid suppressant was similarly higher among cases than controls: H(2)RA users (11.7% [188/1612] vs 8.4% [678/8060], AOR 1.21, 95% CI 1.00-1.46, p<0.048) and PPI users (4.0% [64/1612] vs 2.2% [179/8060], AOR 1.32, 95% CI 0.95-1.84, p=0.094). Use of other drugs was also significantly increased during this period. CONCLUSIONS: Use of acid-suppressing drugs increased before the occurrence of ischemic events regardless of the type (PPI or H(2)RA) or whether other drugs, such as clopidogrel, were concurrently administered. In addition, significant increases in overall drug use were observed during this time frame, suggesting that many patients exhibit warning signs before an acute hospitalization. Thus, PPI use before the occurrence of ischemic events may simply be a marker of unmeasured and uncontrolled confounding in observational studies that have implicated a PPI-clopidogrel interaction as a cause of recurrent ischemic events.
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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 | 0.017 | 0.048 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".