(126 days)
The A1cNow™ test provides quantitative measurement of the percent of glycated hemoglobin (% HbA1c) levels in fingerstick (capillary) whole blood samples. The test is for home use by people with diabetes to monitor glycemic control.
AlcNow™ for Home Use is a four-channel reflectance photometer that incorporates microelectronics, optics, and dry-reagent chemistry strips within a self-contained, integrated, single-use device. An unmeasured whole blood mixture (diluted) is applied directly to the sample port, and results are displayed in numeric form on the device's liquid crystal display after eight minutes. Having no switches or buttons, the device self-activates upon addition of the sample.
A1cNow™ for Home Use utilizes both immunoassay and chemistry technology to measure HbA1c and total hemoglobin, respectively. Upon the addition of a diluted blood sample, blue microparticles conjugated to anti-HbA1c antibody migrate along the reagent strips. The amount of blue microparticles captured on the strips reflects the amount of HbA1c in the sample.
For the total hemoglobin portion of the assay, the dilution of sample converts Hb to met-Hb, which is red-brown in color. The intensity of the red-brown color measured on the reagent strips is proportional to the concentration of hemoglobin in the sample.
Acceptance Criteria and Device Performance for Metrika A1cNow™ for Home Use
Here's a breakdown of the requested information based on the provided 510(k) summary:
1. Acceptance Criteria and Reported Device Performance
| Characteristic | Acceptance Criteria (from predicate/comparison) | Reported Device Performance (A1cNow™ for Home Use) |
|---|---|---|
| Precision | Approximately 6.4 %CV (from A1cNow™ for Rx Home Use K020234) | Approximately 5.4 %CV |
| Accuracy (estimated bias) | Biases of 2-3% across the range of 6% A1C to 8 %A1C (from A1cNow™ for Rx Home Use K020234) | Biases of 1-2% (±0.1 %A1C) across the range of 6 %A1C to 8 %A1C. Average estimated bias less than 2% in clinical studies. |
| Accuracy (total error) | 95% confidence limits of -0.8 %HbA1c to +1.2 %HbA1c (from A1cNow™ for Rx Home Use K020234) | 95% confidence limits of -0.9 % HbA1c to +1.1 %HbAlc |
| Linearity | N/A (implied expectation based on previous submission) | Linear between 3% and 13% HbA1c |
| Hematocrit Tolerance | N/A (implied expectation based on previous submission) | Suitable results with sample hematocrits between 20% and 60% PCV |
| Specificity | N/A (implied expectation based on previous submission) | Assay not affected by high levels of various biological compounds, OTC therapeutics, and oral antihyperglycemic agents. |
| User Accuracy | N/A (no explicit criterion given, but clinical study addresses user performance) | 98% accurate (in clinical studies with untrained subjects) |
Note: The acceptance criteria for the A1cNow™ for Home Use are largely based on demonstrating substantial equivalence to its predicate device, A1cNow™ for Rx Home Use (K020234). Therefore, the "acceptance criteria" column reflects the performance characteristics reported for the predicate device, which the new device aims to meet or exceed.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: Approximately 300 subjects.
- Data Provenance: Not explicitly stated, but the clinical studies involved "untrained subjects," suggesting real-world use or simulation. The document does not specify the country of origin, but it is a US 510(k) submission. It is a prospective study, as it involved untrained subjects using the device.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Number of Experts: Not specified.
- Qualifications of Experts: Not specified. The ground truth was established by a "standard laboratory method."
4. Adjudication Method for the Test Set
- The document does not specify an adjudication method for the clinical study results. The comparison was made between the user's results and a "standard laboratory method."
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not reported. The study focused on the performance of the device when used by individual untrained subjects compared to a laboratory reference method, not on human readers interpreting results with or without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Yes, a standalone performance evaluation was conducted for the device. The nonclinical data (linearity, hematocrit tolerance, precision, specificity) directly address the device's inherent analytical performance independently of human interpretation of results. The device itself is designed for direct numeric output rather than human interpretation of an image or signal.
7. The Type of Ground Truth Used
- The ground truth used was established by a standard laboratory method for measuring %HbA1c.
8. The Sample Size for the Training Set
- The document does not explicitly state a separate training set sample size. This device is a measurement device with dry-reagent chemistry strips and a reflectance photometer, rather than a machine learning or AI-driven algorithm that typically requires a large training dataset. The "training" in this context would likely refer to the initial development and calibration data, which is not detailed as a distinct "training set" in the provided summary. Each unit is factory calibrated.
9. How the Ground Truth for the Training Set Was Established
- The document does not explicitly describe how ground truth for a training set (if one existed in the typical machine learning sense) was established. Given it's a physical device with factory calibration, the "ground truth" for calibration would typically involve a series of known, precisely measured reference samples or calibrators, but the specifics are not provided.
§ 864.7470 Glycosylated hemoglobin assay.
(a)
Identification. A glycosylated hemoglobin assay is a device used to measure the glycosylated hemoglobins (A1a , A1b , and A1c ) in a patient's blood by a column chromatographic procedure. Measurement of glycosylated hemoglobin is used to assess the level of control of a patient's diabetes and to determine the proper insulin dosage for a patient. Elevated levels of glycosylated hemoglobin indicate uncontrolled diabetes in a patient.(b)
Classification. Class II (performance standards).