<sup>13</sup>C Urea Breath Test for<i>Helicobacter pylori</i>: Evaluation of 10-minute Breath Collection
Bibliographic record
Abstract
AIM: To determine whether a shortened (13)C urea breath test ((13)C UBT) (breath collection time of 10 min) is as reliable as the standard assay (30 min). METHODS: Two hundred ninety-seven patients (mean +/- SD: 53+/-16 years, 57% female) completed a (13)C UBT. Breath samples were obtained at baseline and at 5 min intervals up to 30 min. Sixty-seven patients also underwent endoscopic biopsy. Cluster analysis was performed on the (13)C UBT data to determine the optimal cut-off point at each time interval. Sensitivity and specificity of the (13)C UBT at all intervals compared with histology and culture and against the standard 30 min interval were determined. RESULTS: The calculated optimal cut-off points for each time interval (T), expressed as delta over baseline (delta/1000), were 3.29 delta/1000 at T(5), 3.15 delta/1000 at T(10), 3.42 delta/1000 at T(15), 3.17 delta/1000 at T(20), 2.99 delta/1000 at T(25) and 2.82 delta/1000 at T(30). Except at T(5), the risk of false-positive and false-negative test results at each time interval was lower than 2.3% using these cut-off points. When replacing the cut-off points with 3.0 delta/1000, the risk of error was still lower than 2.3%. The test at T(10) showed 98.6% sensitivity and 98.6% specificity compared with T(30). T(10) and T(30) showed 100% sensitivity and 96% specificity compared with histology and culture. CONCLUSIONS: The (13)C UBT is an accurate, noninvasive test, even when the breath sample interval is reduced to 10 min. The present study confirms the validity of a cut-off point of 3.0 delta/1000 for the 10 min and 30 min (13)C UBT.
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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 | 0.002 | 0.006 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| 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 | 0.001 | 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".