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The QMS® Quinidine assay is intended for the quantitative determination of quinidine in human serum or plasma on automated clinical chemistry analyzers.

The results obtained are used in the diagnosis and treatment of quinidine overdose and in monitoring levels of quinidine to help ensure appropriate therapy.

The QMS® Quinidine assay system is a homogeneous assay utilizing particle agglutination technology and is based on the competitive binding principle.

In particle agglutination assays, the degree of agglutination is inversely proportional to the quantity of free drug in the reaction well. Hence, if no drug is present in the sample, the antibodies in the QMS® Quinidine Antibody Reagent (R1) will bind only to the bound drug on the particle which will cause it to agglutinate and will result in higher absorbance. If increased amount of competing drug is present in the sample, this will result in decreased binding of bound drug by the antibody, resulting in a relative decrease in particle agglutination. This in turn results in lower absorbance.

The precise relationship between particle agglutination of the unlabeled drug in the sample is established by measuring the absorbance values of calibrators with known concentration of the The absorbance of unknown samples can be interpolated from the absorbance values of the drug, calibration curve and the concentration of the drug present in the sample can be calculated.

The assay consists of reagents R1: anti-quinidine monoconal and R2: quinidine-oated microparticles. A six-level set of QMS® Quinidine Calibrators (A throu

Here's a breakdown of the acceptance criteria and study information for the QMS® Quinidine assay, based on the provided document:

1. Table of Acceptance Criteria and Reported Device Performance

2. Sample Size Used for the Test Set and Data Provenance

• Accuracy: Samples analyzed in duplicate. The number of samples for the accuracy study was 3 "theoretical concentrations" of quinidine (2.0, 4.0, 8.0 µg/mL), each tested in duplicate (total 6 measurements).
• Linearity: Not explicitly stated as a number of individual samples, but the study was "based on the NCCLS guideline EP6: Evaluation of the Linearity of Quantitative Measurement." It involved testing 5 theoretical concentrations (0.25, 0.75, 1.5, 3.0, 6.0 µg/mL), each in duplicate.
• Method Comparison: N = 50 (number of patient samples)
• Precision: 80 measurements per control level (for 3 control levels, so 240 total measurements).
• Specificity: N=3 for each cross-reactant.
• Interferences (Endogenous Substances): N=2 for Bilirubin and Hemoglobin, N=3 for Triglyceride and Total Protein.
• Interferences (HAMA): Samples analyzed in duplicate for Control, HAMA Type-1, HAMA Type-2.
• Data Provenance: The document does not specify the country of origin for the human serum/plasma samples. It states that accuracy was determined by spiking USP traceable quinidine into "human serum negative for the drug." Method comparison used "patient samples." The studies appear to be retrospective in nature, as they are laboratory-based validation studies.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

This type of information (number and qualifications of experts) is not applicable for this device and study. The QMS® Quinidine assay is an in vitro diagnostic (IVD) device for quantitative determination of a drug in serum/plasma. Its performance is evaluated against established analytical methods and reference standards, not by human expert interpretation of images or clinical data for ground truth.

4. Adjudication Method for the Test Set

This is not applicable as the studies involve quantitative measurements and comparisons to reference values or other assays, not human interpretation requiring 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 done. This type of study is typically used for medical imaging devices where human readers interpret cases with and without AI assistance. This document describes the analytical performance of a quantitative immunoassay.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

Yes, the studies presented are all standalone performance evaluations of the QMS® Quinidine assay. The device itself is an automated clinical chemistry analyzer for quantitative determination, meaning it operates without direct human interpretive input beyond sample loading and results reporting. The performance metrics (accuracy, linearity, precision, etc.) are inherent to the assay's ability to measure quinidine concentrations.

7. The Type of Ground Truth Used

The ground truth for the various studies includes:

• Spiked Concentrations: For accuracy and linearity, USP traceable quinidine was spiked into human serum to create samples with known theoretical concentrations.
• Reference Method Results: For method comparison, the Abbott TDx/TDxFLx Quinidine assay served as the reference method, and its results were compared to the QMS® Quinidine assay.
• Known Concentrations/Materials: For sensitivity, specificity, and interference studies, samples with known concentrations of drug, cross-reactants, or interfering substances were used.

8. The Sample Size for the Training Set

The document describes the validation studies for the QMS® Quinidine assay. For an IVD device like this, the "training set" would typically refer to the data used during the development and optimization of the assay's reagents and methodology. This information is not provided in this 510(k) summary, as it generally focuses on the final validation results, not the developmental process.

9. How the Ground Truth for the Training Set Was Established

As the "training set" information is not provided, the method for establishing its ground truth is also not available in this document. During development, ground truth would likely be established using highly accurate reference methods, certified reference materials, and meticulously prepared known-concentration samples, similar to the validation methods but on a smaller scale and iteratively.

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