(132 days)
HemaPrompt is a guaiac-based in-vitro slide method for the qualitative detection of occult blood in feces by lay persons.
It is a useful aid in the diagnosis or early detection of a number of gastrointestinal disorders, and is recommended for use in monitoring for recurrences of previously treated bowel conditions, and in screening for colorectal cancer or for other sources of gastro-intestinal bleeding.
For Over-The-Counter Use
HemaPrompt is presently approved and being used by health care professionals for the screening of stool for occult blood. It is a guaiac based system using a color change in the test slide to show the presence of a pathological amount of blood in the stool, which indicates the need for further investigation by medical personnel.
HemaPrompt for use at home is the same in configuration and chemical constitution as that currently used by professionals. HemaPrompt is much simpler and safer to use than similar home-use kits because the developing solution is individually contained in each slide thereby obviating the need to measure or handle a potentially hazardous solution. This design also obviates variations in user technique, and because of a "built - in" control monitor, proper function is obvious.
HemaPrompt Device Performance Study Summary
1. Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| User Interpretation Accuracy: No statistically significant variation in test interpretation between lay persons and healthcare professionals. | Observation: A study involving 250 lay persons and 50 nurses showed no statistically significant variation in their ability to perform the test and interpret results. |
| Understandability of Instructions: High understandability rate for critical safety instructions (e.g., "Should you see a physician if your test is positive?"). | Observation: A questionnaire given to 50 lay persons demonstrated a greater than 95% understandability rate for the most important question regarding physician consultation after a positive test. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size:
- Lay persons for interpretation study: 250 individuals
- Nurses for interpretation study: 50 individuals
- Lay persons for instruction understandability: 50 individuals
- Data Provenance: The document does not explicitly state the country of origin. However, given it's a 510(k) submission to the FDA, it can be inferred that the studies were conducted in the US. The studies appear to be prospective as participants were "asked... to perform the test and interpret the results" or given a questionnaire.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The study described focuses on user comprehension and interpretation of the device, rather than the device's diagnostic accuracy against a clinical ground truth. Therefore, the concept of "experts establishing ground truth" for the test results performed by the participants is not directly applicable in the conventional sense. The "ground truth" for the interpretation study was likely the manufacturer's intended correct interpretation of the HemaPrompt test (positive/negative), which the nurses were presumed to already understand.
- Experts for interpretation comparison: 50 nurses who routinely perform fecal occult blood tests in a hospital. Their qualifications are implied by their routine professional experience.
- Experts for instruction revision (implicitly): The "manufacturer" or "experts" involved in revising the instructions based on lay person feedback. No specific number or qualifications are provided.
4. Adjudication Method for the Test Set
The document does not describe an explicit adjudication method (like 2+1 or 3+1). For the interpretation study, the comparison was between the interpretations of lay persons and nurses. The "ground truth" for each specific test read by the participants would be the actual result shown on the HemaPrompt slide (positive/negative), which was then compared to their interpretation. It's not a consensus-based adjudication but rather a direct comparison of individual interpretations against a known expected outcome.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a MRMC comparative effectiveness study involving human readers with and without AI assistance was not mentioned. The device is a diagnostic test itself, not an AI-powered diagnostic aid for human readers.
6. Standalone Performance Study (Algorithm Only Without Human-in-the-loop Performance)
Yes, the HemaPrompt device itself has a standalone performance, albeit implicitly. The submission states that "HemaPrompt for use at home is the same in configuration and chemical constitution as that currently used by professionals." This implies that the chemical reaction and color change (the "algorithm" in this context) of the device functions independently, and its performance (false positive/negative rates) are "no different from the professionally used test." The study then focuses on the user's ability to operate and interpret this standalone device.
7. Type of Ground Truth Used
- For user interpretation accuracy: The ground truth for the study participants' interpretations would be the actual positive or negative result displayed by the HemaPrompt slide for the test specimens they were provided. This is an objective chemical reaction result.
- For the device's clinical efficacy (implied): The text mentions the clinical benefits of early detection and states there is a "recognized false positive and false negative rate which is no different from the professionally used test." This suggests that the ground truth for the device's diagnostic performance implicitly relies on established clinical outcomes and pathology. However, the study described in the 510(k) focuses on user performance, not direct diagnostic accuracy via pathology comparison.
8. Sample Size for the Training Set
The document does not describe a "training set" in the context of an algorithm or AI model. The studies described are for user performance and instruction comprehension.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no "training set" for an algorithm described in this submission. For the user studies, the "training" for the lay persons involved reading the provided instructions.
§ 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.