Comprehensive Age and Sex 99th Percentiles for a High-Sensitivity Cardiac Troponin I Assay
Bibliographic record
Abstract
To the Editor: Cardiac troponin I (cTnI)1 is routinely used to aid in the diagnosis of acute myocardial infarction. Few available cardiac troponin assays have adopted 99th percentiles based on patient demographics. However, there is growing evidence of age and sex differences for cTnI and cardiac troponin T (cTnT), especially when using high-sensitivity cardiac troponin assays, with sex-dependent 99th percentiles being recommended for clinical care (1–3). The Single Molecule Counting (SMCTM) cTnI test (Singulex) can measure cTnI in nearly all healthy individuals (4). We sought to establish the 99th percentile for the SMC cTnI test by deriving an objective definition of “healthy” from >100000 patient results. SMC cTnI is a laboratory-developed test (not cleared by the Food and Drug Administration). The test is a quantitative fluorescent 1-step sandwich immunoassay developed to measure human cTnI concentrations in separated EDTA plasma (5). The lower limit of quantification (LLoQ) was 0.40 ng/L (the lowest standard concentration with back-interpolated recovery bias <20% and CV <20%). The LLoQ was the lowest reliable concentration and the lowest result clinically reported. SMC cTnI results were retrospectively mined from the Singulex patient database (n = 132417) containing data from all-comer …
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.002 | 0.004 |
| 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; both teacher heads agree on what is shown here.
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".