(191 days)
The QMS Zonisamide assay is intended for the quantitative determination of zonisamide in human serum or plasma on automated clinical chemistry analyzers.
Zonisamide concentrations can be used as an aid in management of patients treated with zonisamide.
The QMS® Zonisamide Calibrator set is intended for use in calibration of the QMS Zonisamide assay.
The QMS® Zonisamide Control set is intended for use in quality control of the QMS Zonisamide assay.
The QMS Zonisamide assay system is a homogeneous assay utilizing particle agglutination technology and is based on the competitive binding principle.
The assay consists of reagents R1: anti-Zonisamide rabbit polyclonal antibody and R2: Zonisamidecoated microparticles. A six-level set of QMS® Zonisamide Calibrators (A through F) is used to calibrate the assay. A three-level set of QMS® Zonisamide Controls (1 through 3) is used for quality control of the assay.
The provided text describes the QMS® Zonisamide assay, a homogeneous particle-enhanced turbidimetric immunoassay for the quantitative determination of zonisamide in human serum or plasma. The information focuses on demonstrating its substantial equivalence to a legally marketed predicate device (Innofluor® Phenytoin) through performance testing.
Here's an analysis of the acceptance criteria and the studies performed, formatted as requested:
1. Table of Acceptance Criteria and the Reported Device Performance
| Acceptance Criteria Category | Specific Criteria/Study Goal | Reported Device Performance |
|---|---|---|
| Accuracy and Linearity | To evaluate the accuracy and linearity of the assay | Demonstrated accuracy and linearity based on NCCLS guideline EP6. |
| Sensitivity | Analytical Sensitivity (Least Detectable Dose - LDD) | 1.0 µg/mL |
| Functional Sensitivity (Limit of Quantitation - LOQ) | 3.0 µg/mL | |
| Assay Range | Reportable range for the assay | 3.0 to 50.0 µg/mL (Package insert claim based on Accuracy, Linearity, and Sensitivity data) |
| Method Comparison | Correlation with another method (implicit: to show agreement with a recognized method) | Correlation studies conducted using NCCLS Guideline EP9 (no specific correlation values provided in the summary). |
| Precision | To evaluate the precision performance of the assay | Precision study performed using NCCLS guideline EP5 (no specific precision values provided in the summary). |
| Specificity | No significant cross-reactivity with major metabolites (NAZ and SMAP) | No significant cross-reactivity for NAZ and SMAP. |
| Interferences | No significant cross-reactivity with common interfering substances/drugs | Of 26 drugs tested, none showed cross-reactivity. |
2. Sample Size Used for the Test Set and the Data Provenance
The document does not explicitly state the sample sizes used for the test sets in the accuracy, linearity, method comparison, precision, specificity, or interference studies.
Regarding data provenance:
- The studies were conducted using well-established NCCLS guidelines, implying standardized laboratory testing.
- The method comparison used "patient samples," suggesting a clinical context, but no specifics about country of origin or whether it was retrospective or prospective are provided.
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. The studies described are primarily analytical performance studies of a quantitative assay, where the "ground truth" for assay accuracy and calibration would typically be established by reference methods or gravimetric preparation of standards, not by human expert interpretation.
4. Adjudication Method for the Test Set
This information is not applicable and therefore, not provided. Adjudication methods (like 2+1, 3+1) are typically used in studies involving human interpretation (e.g., image analysis, clinical diagnosis) where there might be inter-reader variability. For an automated quantitative assay, the "ground truth" is typically determined by objective reference methods or precise measurements, not by expert consensus adjudication.
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 performed. This type of study is relevant for diagnostic devices that involve significant human interpretation (e.g., radiologists reading images) and the AI's impact on human performance. The QMS® Zonisamide assay is a quantitative determination assay performed on automated clinical chemistry analyzers, not an interpretive diagnostic tool requiring human readers in that sense.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, the studies described are inherently standalone performance tests of the assay. The QMS® Zonisamide assay is a laboratory test system designed to provide quantitative results directly from automated analyzers. The reported performance metrics (accuracy, linearity, sensitivity, precision, specificity, interferences) evaluate the device's capability to accurately and reliably measure zonisamide concentrations without direct human interpretation influencing the measurement outcome.
7. The Type of Ground Truth Used
The ground truth for this type of quantitative assay would typically be established through:
- Reference Methods / Gravimetric Standards: For accuracy and linearity, highly precise and accurate reference methods or gravimetrically prepared standards with known zonisamide concentrations would be used.
- Known Concentrations: For sensitivity, specificity, and interference studies, samples with precisely known concentrations of zonisamide, metabolites, or interfering substances would be utilized.
- Patient Samples: For method comparison studies, the "ground truth" would be the results obtained from an established comparative method on actual patient samples.
The document does not explicitly detail the exact methods used for establishing ground truth for each study but implies standard laboratory practices using "patient samples" for method comparison and reference to NCCLS guidelines for other analytical performance.
8. The Sample Size for the Training Set
This information is not applicable and therefore, not provided. The QMS® Zonisamide assay is a biochemical immunoassay, not a machine learning or AI algorithm that requires a separate "training set" in the context of supervised learning. The assay's performance is driven by its reagent formulation, reaction kinetics, and instrument calibration, not by an algorithm trained on a dataset.
9. How the Ground Truth for the Training Set Was Established
This information is not applicable as there is no "training set" in the context of an immunoassay. The chemical and biological principles of the assay itself, along with the manufacturing and quality control of the reagents and calibrators, establish its analytical performance capabilities.
§ 862.3350 Diphenylhydantoin test system.
(a)
Identification. A diphenylhydantoin test system is a device intended to measure diphenylhydantoin, an antiepileptic drug, in human specimens. Measurements obtained by this device are used in the diagnosis and treatment of diphenylhydantoin overdose and in monitoring levels of diphenylhydantoin to ensure appropriate therapy.(b)
Classification. Class II.