(65 days)
Immunoassay for the in vitro quantitative determination of Digoman serum and plasma.
Homogeneous enzyme immunoassay for the determination of Digoxin.
The acceptance criteria and study proving the device meets them are described below for the CEDIA Digoxin Assay.
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly present a table of "acceptance criteria" but rather a "Comparison to predicate device" which contains performance characteristics of the CEDIA Digoxin Assay and the predicate device (Abbott TDx® Digoxin II Assay). The acceptance criteria for substantial equivalence are implicitly linked to demonstrating comparable performance to the predicate device.
| Feature | Acceptance Criteria (Implicit - based on Predicate Device) | Reported Device Performance (CEDIA® Digoxin) |
|---|---|---|
| Precision (Within run) | Comparable to TDx Digoxin II (e.g., %CV ~0.96) | Least Squares: y = 0.97x - 0.17, r = 0.9667 (N=99) |
| Deming's: y = 1.00x - 0.22, r = 0.9667 (N=99) | ||
| Interfering Substances | No significant interference at specified levels | Bilirubin (66 mg/dL): No interference |
| Hemoglobin (1000 mg/dL): No interference | ||
| Triglyceride Lipemia (100 mg/dL): No interference | ||
| Total Protein (10 g/dL): No interference | ||
| Rheumatoid Factor (100 IU/mL): No interference | ||
| Specificity (% Cross-reactivity) | Acceptable cross-reactivity profile | Digoxigenin: 59.3%, B-Acetyldigoxin: 71.3%, etc. (detailed in image) |
2. Sample Sizes Used for the Test Set and Data Provenance
- Precision: For "Within run" and "Total" precision, N=120 samples were used for each of three levels (Level 1, Level 2, Level 3) for the CEDIA Digoxin assay. The document does not specify the provenance (e.g., country of origin) or whether the data was retrospective or prospective.
- Method Comparison: N=99 samples were used for the method comparison study against the Abbott TDx Digoxin. The document does not specify the provenance or whether the data was retrospective or prospective.
- Interfering Substances & Specificity: The document does not explicitly state the sample sizes for these tests, implying they were conducted with an appropriate number of samples to demonstrate the stated performance. The provenance and data type are not specified.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
This information is not applicable to an in vitro diagnostic (IVD) assay like the CEDIA Digoxin Assay. Ground truth for such devices is established through laboratory analyses and reference methodologies, not expert consensus in the way clinical image interpretation studies might use radiologists.
4. Adjudication Method for the Test Set
This is not applicable to an IVD assay. Performance is determined by direct comparison to reference methods or to the predicate device's measured performance characteristics.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
This is not applicable as the device is an in vitro diagnostic assay, not an imaging device requiring human reader interpretation. No MRMC study was conducted.
6. If a Standalone (Algorithm Only) Performance Study Was Done
The performance characteristics presented (Precision, Lower Detection Limit, Linearity, Method Comparison, Interfering Substances, Specificity) represent the standalone performance of the CEDIA Digoxin Assay as a laboratory instrument and reagent system. This is the equivalent of a "standalone" performance study for an IVD.
7. The Type of Ground Truth Used
The ground truth for the CEDIA Digoxin Assay performance studies is derived from:
- Reference materials/known concentrations: For precision, linearity, and lower detection limit, control samples or samples with known, verified concentrations of Digoxin would be used.
- Predicate device comparison: For method comparison, the Abbott TDx® Digoxin II Assay serves as the comparator or "reference" for evaluating agreement.
- Spiking studies/known interfering substances: For interfering substances and specificity, samples spiked with known concentrations of potential interferents or cross-reactants are used.
8. The Sample Size for the Training Set
The document does not provide information about a "training set" as this is not typically applicable in the same way to IVD assays. The development and optimization of the assay would involve internal development studies and validation, but these are not usually categorized as distinct "training" datasets in the context of device submission. The presented data represents validation/performance testing data.
9. How the Ground Truth for the Training Set Was Established
As noted in point 8, the concept of a training set with established ground truth as in AI/machine learning is not directly relevant here. The development of the assay would have involved rigorous chemical and biological characterization, using known concentrations and reference methods to achieve the desired performance characteristics.
§ 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.