(104 days)
The INSTANT-VIEW Fecal Occult Blood (FOB) Self-Test is a qualitative immunoassay for the detection of Fecal Occult Blood by non-professional, lay individuals as a self-test product. Measurement of FOB is useful as an aid to detect human blood in stool as found in a number of gastrointestinal disorders, e.g. diverticulitis, colitis, polyps and colorectal cancer. It is intended for over the counter use.
Device is a one-step lateral flow chromatographic immunoassay. The test strip in the device consists of 1) a burgundy-colored conjugate pad containing colloidal gold coupled with mouse anti-human hemoglobin monoclonal antibodies, and 2) nitrocellulose membrane containing a test line (T line) and a control line (C line). The T line is coated with anti-human hemoglobin antibodies, and the C line is coated with goat anti-mouse IgG antibodies. The proposed device has only cassette format. The cassette is a device that contains a dip-strip in a plastic housing.
Here's a breakdown of the acceptance criteria and study information for the INSTANT-VIEW® Fecal Occult Blood (FOB) Self-Test, as extracted from the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Implied/Direct) | Reported Device Performance |
|---|---|---|
| Accuracy | Correlation of 100% with the predicate device (Hemoccult®) for spiked samples. | 100 samples (20 each at 0, 37.5, 50, 62.5, and 2000 ng/ml human hemoglobin) were tested. The correlation between the FOB and the predicate device was 100%. |
| Reproducibility (POL) | Not explicitly stated, but based on results, high agreement with expected. | Evaluations at three Physician's Office Laboratories (POL) showed 97.7% agreement with expected results. |
| Reproducibility (Med Lab) | Not explicitly stated, but based on results, high agreement with expected. | Results obtained from one Medical Laboratory showed 99% agreement with expected results. |
| Reproducibility (Lay Users) | Not explicitly stated, but implied to be high enough for OTC use. | 95% of 120 professional and non-professional lay individuals were able to follow package insert instructions and obtain accurate results (matching professional results). |
| Sensitivity | 50 ng/ml | The sensitivity of the proposed device is 50 ng/ml. |
| Specificity | Specific for human hemoglobin (avoiding false positives from red meats). | It is specific for human hemoglobin. Unlike the predicate (Hemoccult®), it does not give false positive results due to consumption of red meats, etc. |
| Consumer Study (Accuracy) | Consumer results within accepted range for self-test products. | Consumer results agreed 95% with expected results (four false negatives and two false positives). This was deemed within the accepted range. |
| Consumer Study (Usability) | Highly positive feedback on simplicity, speed, convenience, and accuracy. | Over 98% of consumers found the device to be simple, fast, convenient, and accurate. |
| Stability | 2 years at 15-30°C (59-86°F) | The test device is stable when stored in a controlled environment at 15-30°C (59-86°F) for up to two years following manufacturing or until the expiration date, whichever comes first. |
2. Sample Size Used for the Test Set and the Data Provenance
- Accuracy Study (Spiked Samples): 100 samples. The text states these were "collected in-house" so the provenance details beyond that are not specified, but they were artificially spiked with human hemoglobin - suggesting a controlled laboratory setting rather than patient data.
- Reproducibility Study:
- POL Sites: Not explicitly stated, but "three Physician's Office Laboratories" were used. The number of tests performed at these sites isn't detailed, only the agreement rate.
- Medical Laboratory: Not explicitly stated, but "one Medical Laboratory" was used. The number of tests performed isn't detailed.
- Lay Individuals: 120 professional and non-professional lay individuals.
- Consumer Study: Likely the same 120 individuals mentioned in the reproducibility study for lay users.
The provenance is mixed:
- Accuracy: Likely laboratory-controlled specimens (feces extraction specimens spiked with hemoglobin).
- Reproducibility: Involved external POLs and a Medical Laboratory, and a group of "professional and non-professional lay individuals." The data collection seems prospective for the reproducibility and consumer studies, as individuals were actively performing tests.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts
The document does not explicitly state the number or qualifications of experts used to establish a "ground truth" in the traditional sense for the test set.
- For the Accuracy study, the ground truth was based on the known concentrations of human hemoglobin spiked into the samples. The predicate device (Hemoccult®) was also used for comparison, implying its results (for those concentrations) served as a reference.
- For the Reproducibility study, the "expected results" were used. For the lay user portion, professionals also tested the samples, so their results served as a comparative ground truth.
- For the Consumer study, the "expected results" and "results obtained by professionals" served as the ground truth against which consumer performance was compared.
4. Adjudication Method for the Test Set
The document does not specify a formal adjudication method (like 2+1 or 3+1). For reproducibility and consumer studies, consumer/lay results were compared against "expected results" or "results obtained by professionals," implying a simple comparison rather than a multi-reader adjudication process.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was Done, If So, what was the effect size of how much human readers improve with AI vs without AI assistance
No, a Multi Reader Multi Case (MRMC) comparative effectiveness study was not done. This device is an in-vitro diagnostic (IVD) self-test, not an AI-assisted diagnostic tool for human readers. Therefore, there's no mention of how human readers improve with AI assistance.
6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was done
This refers to a diagnostic device, not an algorithm. The device itself (the immunoassay) performs the diagnostic function. The "standalone" performance here refers to the device's ability to accurately detect FOB. The accuracy, sensitivity, and specificity studies essentially demonstrate the standalone performance of the device.
7. The Type of Ground Truth Used
- Accuracy: Known concentrations of spiked human hemoglobin. Comparison to a predicate device (Hemoccult®).
- Reproducibility: "Expected results" (likely determined by the manufacturer or expert testing in a controlled environment). For lay users, professional results served as the reference.
- Consumer Study: "Expected results" and "results obtained by professionals."
8. The Sample Size for the Training Set
The document does not mention a "training set" in the context of machine learning or AI. This is a traditional IVD device, not an AI-based one. All sample sizes mentioned pertain to validation/testing or performance evaluation.
9. How the Ground Truth for the Training Set Was Established
As there is no mention of a training set, this question is not applicable.
§ 864.6550 Occult blood test.
(a)
Identification. An occult blood test is a device used to detect occult blood in urine or feces. (Occult blood is blood present in such small quantities that it can be detected only by chemical tests of suspected material, or by microscopic or spectroscopic examination.)(b)
Classification. Class II (special controls). A control intended for use with an occult blood test is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9.