(196 days)
Uriscreen is a non-quantitative rapid screen for the detection of Urinary Tract Infection. Uriscreen detects both bacteria and/or white blood cells, common indicators of Urinary Tract Infection.
Uriscreen is a non-quantitative rapid screen, which detects catalase. Urinary catalase may be associated with White Blood Cells, bacteria and other cells, some of which may be indicators of urinary tract infection. Only Adults should use the test.
Uriscreen - Uriscreen is a rapid screen for the detection of Urinary Tract Infection. Uriscreen detects Catalase activity. Most organisms that commonly cause Urinary Tract Infection are Catalase positive. Additionally, Catalase activity is an indicator of white blood cells in urine. White blood cells are a common indicator of Urinary Tract Infection.
Uriscreen tubes contain a reagent powder, which enables Catalase detection. Urine is added to the tube to the line indicated, a few drops of hydrogen peroxide solution are added. Production of foam indicates Catalase activity. Catalase activity is indicative of bacteria and/or white blood cells in the urine. Most bacteria that commonly cause urinary tract infection are Catalase positive. The presence of bacteria and/or white blood cells in the urine are clearly indicative of Urinary Tract Infection.
The manufacturer did not define acceptance criteria. Here's a summary of the performance data from the studies:
1. Acceptance Criteria and Reported Device Performance:
| Study/Comparison | Performance Metric | Reported Performance |
|---|---|---|
| Phase I: Uriscreen vs. Multistix Nitrite/LE | Sensitivity | 100.00% |
| (Lay consumer) | Specificity | 87.34% |
| Accuracy | 89.13% | |
| Phase I: Uriscreen vs. Uri-Test Nitrite in Urine | Sensitivity | 80.00% |
| (Lay consumer) | Specificity | 88.31% |
| Accuracy | 86.96% | |
| Phase I: Uriscreen vs. Reference Culture Method | Sensitivity | 100.00% |
| (Lay consumer) | Specificity | 85.19% |
| Accuracy | 86.96% | |
| Phase II: Consumer vs. Medical Technologist | Sensitivity | 100.00% |
| Specificity | 100.00% | |
| Accuracy | 100.00% | |
| Phase III: Uriscreen vs. Culture (>100,000 CFU/ml) | Sensitivity | 95.35% |
| (Clinical Labs) | Specificity | 72.92% |
| Accuracy | 79.86% | |
| Phase III: Uriscreen vs. Culture (10,000-100,000 CFU/ml) | Sensitivity | 82% |
| (Clinical Labs) | Specificity | 87% |
| Accuracy | 84% |
2. Sample Size and Data Provenance (Test Set):
- Phase I (Lay Consumer comparisons):
- Multistix Nitrite/LE vs. Uriscreen: Total of 92 samples (13 Uriscreen+/Multistix+, 10 Uriscreen+/Multistix-, 0 Uriscreen-/Multistix+, 69 Uriscreen-/Multistix-).
- Uri-Test Nitrite in Urine vs. Uriscreen: Total of 92 samples (12 Uriscreen+/Nitrite+, 9 Uriscreen+/Nitrite-, 3 Uriscreen-/Nitrite+, 68 Uriscreen-/Nitrite-).
- Culture vs. Uriscreen: Total of 92 samples (11 Uriscreen+/Culture+, 12 Uriscreen+/Culture-, 0 Uriscreen-/Culture+, 69 Uriscreen-/Culture-).
- Provenance: Not explicitly stated, but implies collected as part of a clinical trial by the sponsor, likely prospective, with consumers performing the test on their own urine.
- Phase II (Consumer vs. Medical Technologist):
- Sample Size: 65 blinded samples (water only and water + yeast at 10 CFU/ml).
- Provenance: Samples tested by participants at a social club and MDC Associates. Prospective, with "blinded samples."
- Phase III (Clinical Laboratories):
- Uriscreen vs. Culture (>100,000 CFU/ml): 139 samples (41 Uriscreen+/Culture+, 26 Uriscreen+/Culture-, 2 Uriscreen-/Culture+, 70 Uriscreen-/Culture-).
- Uriscreen vs. Culture (≥10,000 to >100,000 CFU/ml): 139 samples (58 Uriscreen+/Culture-Pos, 9 Uriscreen+/Culture-Neg, 13 Uriscreen-/Culture-Pos, 59 Uriscreen-/Culture-Neg).
- Provenance: Conducted in three CLIA Registered Clinical Laboratories, including patients presenting with symptoms of Urinary Tract Infection. Likely prospective.
3. Number and Qualifications of Experts for Ground Truth (Test Set):
- Phase I: Not explicitly stated. For "reference culture method," it implies standard laboratory procedures, but the number and qualifications of experts interpreting these are not detailed.
- Phase II: "A trained Medical Technologist" confirmed all consumer results. Number of technologists not specified.
- Phase III: "Culture" results were used as ground truth. This implies microbiology laboratory professionals performed and interpreted these cultures. The number and specific qualifications of these experts are not explicitly stated, but standard clinical laboratory practices would apply.
4. Adjudication Method (Test Set):
- The document does not describe an adjudication method for conflicting results between experts.
- In Phase II, a single "trained Medical Technologist" confirmed consumer results, implying a direct comparison rather than an adjudication process for conflicting expert opinions.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No MRMC comparative effectiveness study was done to assess how much human readers improve with AI vs. without AI assistance. The Uriscreen is a rapid diagnostic test, not an AI-assisted diagnostic tool for human readers. Phase II did compare consumer interpretation to a medical technologist, but this was to validate consumer use, not human reader improvement with AI.
6. Standalone (Algorithm Only) Performance:
- The Uriscreen itself is a standalone test that produces a result (foam for positive, no foam for negative). The performance data presented (e.g., Sensitivity, Specificity, Accuracy) are representative of the device's standalone performance compared to various benchmarks. There is no separate "algorithm only" component as it's a reagent-based test.
7. Type of Ground Truth Used:
- Phase I:
- Predicate devices (Bayer Multistix Leukocyte esterase/Nitrite and Uri-Test Nitrite in Urine).
- Reference culture method.
- Phase II: Blinded samples (water/yeast) with results confirmed by a "trained Medical Technologist."
- Phase III: Reference culture method, with a positive culture defined as >100,000 CFU/ml or ≥10,000 to >100,000 CFU/ml based on the specific analysis. This is a definitive laboratory standard for bacterial infection.
8. Sample Size for the Training Set:
- This device is a rapid diagnostic test using visual interpretation of a chemical reaction. It is not an algorithm or AI model that typically requires a "training set" in the computational sense. Therefore, there is no training set mentioned or applicable for this type of device.
9. How Ground Truth for the Training Set Was Established:
- As stated above, there is no "training set" for this type of device. The development of the Uriscreen likely involved R&D and optimization of the chemical formulation and reaction parameters based on scientific principles of catalase detection, rather than machine learning training on a dataset with established ground truth.
§ 866.2660 Microorganism differentiation and identification device.
(a)
Identification. A microorganism differentiation and identification device is a device intended for medical purposes that consists of one or more components, such as differential culture media, biochemical reagents, and paper discs or paper strips impregnated with test reagents, that are usually contained in individual compartments and used to differentiate and identify selected microorganisms. The device aids in the diagnosis of disease.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 866.9.