(31 days)
The BinaxNOW® G6PD (Glucose-6-Phosphate Dehydrogenase) Test is an in vitro enzyme chromatographic test for the qualitative detection of G6PD enzyme activity in human venous whole blood, collected in heparin or ethylenediaminetetraacetic acid (EDTA). The BinaxNOW® G6PD Test is a visual screening test used for differentiating normal from deficient G6PD activity levels in whole blood and is intended to aid in the identification of people with G6PD deficiency. Samples which generate deficient results should be assayed using a quantitative G6PD test method to verify the deficiency.
The BinaxNOW® G6PD test device consists of a lateral flow test strip comprised of a white sample pad and a reaction pad, which is located at the top of the strip. The reaction pad contains the reagents necessary for the G6PD enzymatic reaction and the subsequent reduction of a nitro blue tetrazolium dye into its concomitant blue formazan product. The resulting color change on the strip indicates enough G6PD activity is present to presume the sample is not deficient.
To perform the test, a whole blood sample is mixed with red blood cell (RBC) lysing reagent in a sample preparation vial and then transferred to the test device sample pad. The lysed blood sample migrates up the test strip, reconstituting reagents in the reaction pad. When the sample front (or liquid migration) covers the entire reaction pad, the device is closed.
Test results are read visually. If no change in the red color of the sample front is observed at the test read time, the sample is presumed to be deficient in G6PD enzyme activity. Samples normal in G6PD activity produce a distinct color change – the red sample color changes to a brown / black color on the upper half of the reaction pad.
Here's a breakdown of the acceptance criteria and study details for the BinaxNOW® G6PD Test, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Heparin Samples: | ||
| Deficient Result Percent Agreement | > 90% (Commonly accepted for diagnostic tests, though not explicitly stated as an "acceptance criterion" in this document) | 98.0% (CI = 89.3 - 99.6%) |
| Normal Result Percent Agreement | > 90% | 97.9% (CI = 94.8 - 99.2%) |
| Overall Percent Agreement | > 90% | 97.9% (CI = 95.3 - 99.1%) |
| EDTA Samples: | ||
| Deficient Result Percent Agreement | > 90% | 98.0% (CI = 89.5 - 99.6%) |
| Normal Result Percent Agreement | > 90% | 97.4% (CI = 94.2 - 98.9%) |
| Overall Percent Agreement | > 90% | 97.6% (CI = 94.8 - 98.9%) |
| Agreement between Heparin and EDTA | > 95% (Indicates consistency in performance across different anticoagulants) | 99% |
| Interfering Substances | No interference from specified endogenous blood components or copper sulfate; Performance may be affected by extreme hematocrit levels. | None of the endogenous blood components (bilirubin, triglycerides, total cholesterol, lactate dehydrogenase, glucose) affected test performance. Copper sulfate also did not affect performance. Performance was affected by abnormally low (17-18%) and high (54-65%) hematocrit levels. |
| Reproducibility (Across sites/operators) | High agreement with expected results (e.g., >95%) | 98.4% (123/125) agreement with expected test results, with no significant differences within run, between run, between sites, or between operators. |
| Precision (Single operator) | Consistent results over time for known normal/deficient samples (e.g., 100% agreement) | Normal samples interpreted as normal 100% of the time over 10 days. Deficient samples interpreted as deficient 100% of the time over 10 days. |
Note: The document doesn't explicitly state numerical acceptance criteria for agreement percentages, but the reported performance levels clearly exceed commonly accepted efficacy thresholds for diagnostic devices (typically >90% sensitivity and specificity, or equivalent agreement).
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 246 subjects.
- Data Provenance:
- Country of Origin: U.S.
- Retrospective or Prospective: Prospective study conducted in 2007-2008.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not specify the number of experts used or their qualifications to establish the ground truth.
4. Adjudication Method for the Test Set
The document does not describe an adjudication method for the test set. The ground truth was established by a "commercially available quantitative G6PD test."
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
This is an in vitro diagnostic (IVD) device, not an AI-assisted diagnostic imaging device that involves human readers interpreting images. Therefore, an MRMC comparative effectiveness study comparing human readers with and without AI assistance is not applicable and was not performed. The "reading" of the BinaxNOW test is a visual interpretation of a color change by a single operator.
6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was done
The BinaxNOW® G6PD Test is a visual screening test, which inherently involves a "human-in-the-loop" for interpretation of the color change. It is not an algorithm-only device. Therefore, a standalone performance study in the context of an algorithm-only device is not applicable in the typical sense for this product. The studies presented are the standalone performance of the test as it is intended to be used (visually read).
7. The Type of Ground Truth Used
The ground truth was established by a "commercially available quantitative G6PD test." This is a reference method, often considered a "gold standard" for determining the actual G6PD activity levels.
8. The Sample Size for the Training Set
The document does not mention a separate "training set" in the context of machine learning or AI. The BinaxNOW® G6PD Test is a lateral flow assay, not a machine learning algorithm that requires training data in the typical sense. The "performance summary" sections describe clinical validation studies rather than algorithm training.
9. How the Ground Truth for the Training Set Was Established
As noted above, there isn't a "training set" for an algorithm in the context of this device. The development of the device itself would have involved laboratory optimization using known samples (with ground truth established by quantitative G6PD assays), but this is part of product development and not typically referred to as an "algorithm training set" in the regulatory submission for this type of IVD.
§ 864.7360 Erythrocytic glucose-6-phosphate dehydrogenase assay.
(a)
Identification. An erythrocytic glucose-6-phosphate dehydrogenase assay is a device used to measure the activity of the enzyme glucose-6-phosphate dehydrogenase or of glucose-6-phosphate dehydrogenase isoenzymes. The results of this assay are used in the diagnosis and treatment of nonspherocytic congenital hemolytic anemia or drug-induced hemolytic anemia associated with a glucose-6-phosphate dehydrogenase deficiency. This generic device includes assays based on fluorescence, electrophoresis, methemoglobin reduction, catalase inhibition, and ultraviolet kinetics.(b)
Classification. Class II (performance standards).