(143 days)
The FlexSure® HP test for IgG antibodies to H. pylori in whole blood is a rapid, visually read, qualitative immunochromatographic method. The test is for use by health professionals as an aid in the diagnosis of H. pylori infection in patients with clinical signs and symptoms of gastrointestinal disease.
The FlexSure® HP test for IgG antibodies to H. pylori in whole blood is a rapid, visually read, qualitative immunochromatographic method.
The FlexSure® HP Test for IgG Antibodies to H. pylori in Whole Blood is a rapid, visually read, qualitative immunochromatographic method designed as an aid in diagnosing H. pylori infection in patients with gastrointestinal symptoms.
Here's an analysis of the acceptance criteria and the studies performed:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are not explicitly stated as target percentages in the provided text. However, the performance of the FlexSure® HP Whole Blood test is presented in comparison to a predicate device (FlexSure® HP Serum test) and a gold standard (histology and/or urease test), as well as within specific groups (symptomatic patients, volunteer blood donors). The "acceptance criteria" are implied by demonstrating substantial equivalence to the predicate and acceptable performance against the gold standard.
| Performance Metric | Acceptance Criteria (Implied by Predicate Performance) | FlexSure® HP Whole Blood Performance (Reported) - Symptomatic Patients | FlexSure® HP Whole Blood Performance (Reported) - Volunteer Blood Donors |
|---|---|---|---|
| Relative Sensitivity (vs. FlexSure® HP Serum) | 95% (FlexSure® HP Serum vs. ELISA) | 92% (without resolution) | |
| 95% (with resolution) | Not Determined (meaningful comparison not possible without H. pylori confirmation) | ||
| Relative Specificity (vs. FlexSure® HP Serum) | 94% (FlexSure® HP Serum vs. ELISA) | 91% (without resolution) | |
| 94% (with resolution) | 99% | ||
| Overall Agreement (vs. FlexSure® HP Serum) | 95% (FlexSure® HP Serum vs. ELISA) | 92% (without resolution) | |
| 95% (with resolution) | 97% | ||
| Relative Sensitivity (vs. Histology/Urease) | 92% (FlexSure® HP Serum vs. Histology/Urease) | 88% | Not Applicable |
| Relative Specificity (vs. Histology/Urease) | 76% (FlexSure® HP Serum vs. Histology/Urease) | 74% | Not Applicable |
| Overall Agreement (vs. Histology/Urease) | 84% (FlexSure® HP Serum vs. Histology/Urease) | 82% | Not Applicable |
| Within-site Reproducibility | Not explicitly stated | 96% | N/A |
| Between-site Reproducibility | Not explicitly stated | 89% | N/A |
2. Sample Sizes Used for the Test Set and Data Provenance
- Whole Blood Test Set (Symptomatic Patients): 173 patients
- Data Provenance: Multi-center trial at six different gastroenterology clinics located in the United States, Canada, and the United Kingdom. This indicates a prospective and multi-national study.
- Whole Blood Test Set (Volunteer Blood Donors): 233 volunteer blood donors
- Data Provenance: Not explicitly stated, but implies a prospective collection for this specific study.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not explicitly state the number of experts used for establishing the ground truth when comparing the FlexSure® HP Whole Blood test against histology and/or urease tests.
- Qualifications of Experts: Not specified. However, the use of "histology" and "urease test" implies analysis by qualified laboratory personnel, likely pathologists, gastroenterologists, or trained technicians, but specific qualifications (e.g., years of experience) are not provided.
4. Adjudication Method for the Test Set
- For comparisons against FlexSure® HP Serum test:
- An adjudication method was used to resolve discordant serological results. This involved using "histology and/or a urease test." The specific process (e.g., how conflicting histology vs. urease results were handled, or if multiple readings were done) is not detailed.
- For comparisons directly against histology and/or urease test:
- The "ground truth" was established by histology and/or urease test. No further adjudication of these primary methods is described within the context of the whole blood test performance.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
No, an MRMC comparative effectiveness study involving human readers with and without AI assistance was not conducted. This device is a diagnostic test for H. pylori antibodies, not an imaging or interpretation aid for human readers in the way an AI would be.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
Yes, the studies presented are for the standalone performance of the FlexSure® HP Whole Blood test. It is a visually read, qualitative immunochromatographic method, which is inherently a standalone "algorithm" (the test strips chemical reaction and visual result) without a human-in-the-loop performance component in the traditional sense of AI-assisted diagnostics. The human simply reads the result produced by the device.
7. The Type of Ground Truth Used
- For comparison against the predicate device (FlexSure® HP Serum test): The ground truth for the predicate device itself was established by comparison with a commercial microwell ELISA serological test. For the FlexSure® HP Whole Blood test, the FlexSure® HP Serum test was used as a comparator, and discordant results were further resolved by histology and/or urease test (which are forms of pathology/diagnostic testing).
- For direct comparison of FlexSure® HP Whole Blood test: The ground truth was established by histology and/or urease test. These are direct diagnostic methods for H. pylori infection, often considered the gold standard.
8. The Sample Size for the Training Set
The provided text describes performance evaluation studies, not the development or training of the device. Therefore, a "training set" sample size for the FlexSure® HP Whole Blood test is not applicable or provided. The "basic methodology and format" were established previously with the FlexSure® HP Serum test.
9. How the Ground Truth for the Training Set Was Established
As no training set is described for the FlexSure® HP Whole Blood test, this information is not applicable or provided. The FlexSure® HP Serum test's performance characteristics, which presumably formed the basis for the FlexSure® HP Whole Blood test development, were established by comparison with a commercial microwell ELISA serological test, histology, and 13C-urea breath test.
§ 866.3110
Campylobacter fetus serological reagents.(a)
Identification. Campylobacter fetus serological reagents are devices that consist of antisera conjugated with a fluorescent dye used to identifyCampylobacter fetus from clinical specimens or cultured isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by this bacterium and provides epidemiological information on these diseases.Campylobacter fetus is a frequent cause of abortion in sheep and cattle and is sometimes responsible for endocarditis (inflammation of certain membranes of the heart) and enteritis (inflammation of the intestines) in humans.(b)
Classification. Class I (general controls).