(29 days)
The AxSYM Digoxin III assay is a microparticle enzyme immunoassay (MEIA) for the quantitative measurement of digoxin, a cardiovascular drug, in serum or plasma. The measurements obtained are used in the treatment of digoxin overdose and in monitoring levels of digoxin to ensure appropriate therapy.
The AxSYM Digoxin III Reagent Pack is composed of the following reagent components: • Digoxin: Alkaline Phosphatase Conjugate • Anti-digoxin (Rabbit) Coated Microparticles • MEIA Buffer • Digoxin III Probe Wash Solution
The AxSYM Digoxin III Calibrators contain six bottles of accurately measured amounts of digoxin prepared in recalcified human plasma, nonreactive for HBsAg, HIV-1 RNA or HIV-1 Ag, anti-HCV, and anti-HIV-1/HIV-2.
The AxSYM Digoxin III Controls contain three bottles of accurately measured amounts of digoxin prepared in recalcified human plasma, nonreactive for HBsAg, HIV-1 RNA or HIV-1 Ag, anti-HCV, and anti-HIV-1/HIV-2.
Here's a summary of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance:
The document primarily focuses on demonstrating substantial equivalence to a predicate device by comparing attributes and performance characteristics. While explicit "acceptance criteria" in a traditional sense (e.g., specific thresholds for accuracy, precision) are not fully detailed as a separate section, the comparison points serve as acceptance criteria for demonstrating equivalence.
| Acceptance Criterion (Attribute) | Predicate Device Performance (AxSYM Digoxin II) | Modified Device Performance (AxSYM Digoxin III) | Met/Not Met (Based on comparison) |
|---|---|---|---|
| Analyte Measured | Digoxin | Same | Met |
| Assay Principle | MEIA technology, competitive format | Same | Met |
| Instrumentation | Abbott AxSYM Analyzer | Same | Met |
| Sample Type | Serum or plasma | Same | Met |
| Sample Volume | 150 µL (Routine), 131 µL (STAT) | 194 µL (Routine and STAT) | Met (Change noted, but acceptable) |
| Sample Pretreatment | No | No | Met |
| Assay Type | Quantitative | Same | Met |
| Dynamic Range | 0.0 to 4.0 ng/mL (0.00 to 5.12 nmol/L) | Same | Met |
| Calibrator Values | 0.0, 0.5, 1.0, 2.0, 3.0, and 4.0 ng/mL | Same | Met |
| Control Values | 0.9, 1.9, and 3.2 ng/mL | Same | Met |
| Sensitivity | 0.3 ng/mL (0.38 nmol/L) | Same | Met |
| Immunoassay Format | 2-step | 1-step | Met (Change noted, but acceptable) |
| Saponin (%) in Conjugate Diluent | 0.13 | 0.3 | Met (Change noted, but acceptable) |
| Antibody | Rabbit Polyclonal | Same | Met |
| Conjugate | Digoxin: Alkaline Phosphatase | Same | Met |
| Bilirubin Interference at 20 mg/dL | Less than 10% | Less than 20% | Met (Within acceptable range) |
| Drug Compound Interference (Aldosterone inhibitors and other steroids) | -33% to -3% | -2% to 2% | Met (Showed improvement) |
| Probe Wash Solution Ingredients | 2 M sodium chloride 0.1% sodium azide | 2 M sodium chloride 0.1% sodium azide 0.5% Triton X-100 0.05% antifoam | Met (Change noted, but acceptable) |
| Medium Control Range (Target: 1.9 ng/mL) | 1.50 to 2.30 ng/mL | 1.43 to 2.38 ng/mL | Met (Similar range) |
| High Control Range (Target: 3.2 ng/mL) | 2.60 to 3.80 ng/mL | 2.50 to 3.90 ng/mL | Met (Similar range) |
The overall conclusion is: "Results of laboratory testing demonstrate that the performance of the Abbott AxSYM Digoxin III assay is acceptable and comparable to the performance of the predicate device, when used according to its intended use." This statement confirms all criteria were met to achieve substantial equivalence.
2. Sample size used for the test set and the data provenance:
The document does not explicitly state the sample size used for the test set or the data provenance (e.g., country of origin, retrospective/prospective). It only mentions "Results of laboratory testing."
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
This information is not provided in the document. For an in vitro diagnostic device like this, the "ground truth" would likely be established through reference methods or highly accurate comparative assays rather than expert interpretation.
4. Adjudication method for the test set:
This information is not provided.
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 device (IVD) for quantitative measurement of a drug in serum/plasma. It is not an AI-assisted diagnostic imaging device or one that involves human "readers" in the context of interpretation. Therefore, an MRMC comparative effectiveness study involving human readers and AI assistance is not applicable and was not performed.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
The AxSYM Digoxin III assay is an automated in vitro diagnostic device. The performance data presented (e.g., interference, control ranges) represent the standalone performance of the assay system itself, without direct human intervention in the interpretive process of the result once generated by the instrument.
7. The type of ground truth used:
While not explicitly detailed, for an IVD test measuring drug levels, the "ground truth" would typically be established by:
- Reference Methods: Highly accurate and validated analytical techniques (e.g., mass spectrometry) to determine the true concentration of digoxin in samples.
- Known Concentrations: Use of samples with precisely known concentrations of digoxin (e.g., spiked samples, certified reference materials).
8. The sample size for the training set:
The document does not provide information about a "training set" or its sample size. For an IVD assay like this, development typically involves method optimization and validation rather than machine learning training sets in the computational sense.
9. How the ground truth for the training set was established:
As no training set is discussed or implied, this information is not provided.
§ 862.3320 Digoxin test system.
(a)
Identification. A digoxin test system is a device intended to measure digoxin, a cardiovascular drug, in serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of digoxin overdose and in monitoring levels of digoxin to ensure appropriate therapy.(b)
Classification. Class II.