Cardiac Procedure Use and Outcomes in Elderly Patients with Acute Myocardial Infarction in the United States and Quebec, Canada, 1988 to 1994
Bibliographic record
Abstract
BACKGROUND: Studies from the early 1990s have documented greater intensity of treatment for patients with acute myocardial infarction (AMI) in the United States compared with Canada, with little difference in health outcomes. Little is known about whether treatments and outcomes are changing differently over time in the two countries, and whether the differences vary with patient age. METHODS: We conducted a retrospective cohort study of trends in cardiac procedure use, mortality, and recurrent AMI for patients 65 years or older hospitalized with AMI in the United States and Quebec. We examined Medicare claims and enrollment data from the United States (1.5 million) and provincial claims data from Quebec (35,000) between 1988 and 1994. RESULTS: Use of cardiac procedures grew more rapidly between 1988 and 1994 in the United States, particularly for patients 75 years or older; unlike in Quebec, these cardiac procedures were performed soon after AMI. Both countries experienced significant declines in 1-year mortality: the decline averaged 1.27% points per year in the United States and 1.05% points in Quebec (P = ns). For AMI patients 75 years or older, 30-day and 1-year mortality declined approximately twice as rapidly in the United States as in Quebec (P < 0.01). The decline in mortality in the United States relative to Canada was significantly greater among patients 75 years or older but not among those age 65 to 74 years. Readmission rates with recurrent AMI were almost unchanged. CONCLUSIONS: Over time, the use of cardiac procedures in elderly patients with AMI has risen more rapidly in the United States than in Quebec. These differences in procedure trends were associated with reductions in overall long-term AMI mortality in both countries.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| 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".