(97 days)
The Hemosure™ One-Step Fecal Occult Blood (FOB) Test is an immunochemical device intended for the qualitative detection of Fecal Occult Blood by laboratories or physicians offices. It is useful to determine gastrointestinal (GI) bleeding found in a number of GI disorders, e.g. diverticulitis, colitis, polyps, and colorectal cancer.
The Hemosure™ One-Step FOB Test is a lateral flow immunoassays intended for the detection of fecal occult blood.
Here's a breakdown of the acceptance criteria and study details for the Hemosure™ One-Step Fecal Occult Blood (FOB) Test, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Stated or Implied) | Reported Device Performance |
|---|---|
| Sensitivity | |
| Detect human hemoglobin at 50 ng hHb/mL | 100% positive results for samples ≥ 50 ng hHb/mL |
| Specificity/Non-interference | |
| No interference from dietary substances | Stated: "Neither dietary substances nor toilet water fresheners or cleansers interfere" |
| No interference from toilet water | Stated: "Neither dietary substances nor toilet water fresheners or cleansers interfere" |
| No cross-reactivity with non-human hemoglobin | Stated: "does not cross-react with hemoglobin from other species." |
| Positive results only for human hemoglobin | Stated: "gives positive results only when human hemoglobin with sufficient concentration is present." |
| Overall Accuracy | |
| N/A (implied high agreement with expected results) | Overall accuracy: 98% |
| Agreement with predicate device (for sensitivity) | 100% agreement with predicate device (for sensitivity at concentrations ≥ 50 ng hHb/mL) |
2. Sample Size Used for the Test Set and Data Provenance
- Sensitivity Test Set:
- Sample Size: 50 extracted stool samples.
- Data Provenance: "collected in house" - implies internal to WHPM, Inc. Retrospective, as samples were collected and then spiked.
- Overall Accuracy Test Set:
- Sample Size: 100 extracted stool samples.
- Data Provenance: "collected in house" - implies internal to WHPM, Inc. Retrospective, as samples were collected and then spiked.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
The document does not mention the use of experts to establish the ground truth for the test set. Instead, the ground truth was established by spiking known concentrations of human hemoglobin into negative stool samples.
4. Adjudication Method for the Test Set
No adjudication method is mentioned. The ground truth was established by direct spiking of known concentrations of human hemoglobin. The "expected results" were based on these known concentrations.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not explicitly described. The study involved testing the device at different laboratories (physician's office, reference laboratory, WHPM Inc. laboratory), which suggests multiple readers, but it does not detail a comparison of human readers with vs. without AI assistance. This is a diagnostic device, not an AI-assisted diagnostic tool.
6. Standalone (i.e. algorithm only without human-in-the-loop performance) Study
Yes, a standalone study was performed. The device, an immunoassay, is designed to be read directly. The "studies were performed in three sites" and "tested with the Hemosure™ One-Step FOB Test" directly, meaning the device's performance itself was evaluated against known ground truth without human interpretive assistance being measured as a variable.
7. Type of Ground Truth Used
The ground truth used was known concentrations of spiked human hemoglobin (hHb) in stool samples that were initially free of human hemoglobin. This is an engineered ground truth for analytical performance rather than a clinical ground truth from patient outcomes or pathology.
8. Sample Size for the Training Set
The document does not specify a separate training set or its sample size. For an immunoassay device, the "training" typically refers to the development and optimization of the assay itself, rather than training a machine learning algorithm.
9. How the Ground Truth for the Training Set Was Established
As no specific training set for an algorithm is mentioned, this question is not directly applicable. For the device's development/optimization, the ground truth would likely have been established through controlled experiments with known concentrations of analytes, similar to how the test set's ground truth was established.
§ 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.