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The QMS® Vancomycin assay is intended for the quantitative determination of vancomycin in human serum or plasma on the Hitachi 717 analyzer.

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

The QMS® Vancomycin assay is a homogeneous particle-enhanced turbidimetric immunoassay. The assay is based on competition between drug in the sample and drug coated onto a microparticle for antibody binding sites of the vancomycin antibody reagent. The vancomycin-coated microparticle reagent is rapidly aqglutinated in the presence of the anti-vancomycin antibody reagent and in the absence of any competing drug in the sample. The rate of absorbance change is measured photometrically, and is directly proportional to the rate of agglutination of the particles. When a sample containing vancomycin is added, the agglutination reaction is partially inhibited, slowing down the rate of absorbance change. A concentrationdependent classic agglutination inhibition curve can be obtained, with maximum rate of agglutination at the lowest vancomycin concentration and the lowest agglutination rate at the highest vancomycin concentration.

The assay consists of reagents R1: vancomycin monoclonal and R2: vancomycin-coated microparticles. A six-level set of QMS® Vancomycin Calibrators (A through F) i

Here's a summary of the acceptance criteria and study findings for the QMS® Vancomycin assay, based on the provided 510(k) summary:

Acceptance Criteria and Device Performance for QMS® Vancomycin Assay

1. Table of Acceptance Criteria and Reported Device Performance

The provided document does not explicitly state pre-defined "acceptance criteria" with numerical thresholds for all tests. Instead, it presents study results and implies that the observed performance characteristics were deemed acceptable for substantial equivalence to the predicate device. For the purpose of this table, "Acceptance Criteria (Implied)" are derived from the overall goal of demonstrating equivalency or typical performance expectations for such assays, and "Reported Device Performance" are the results presented in the summary.

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

• Precision: 80 replicates for each of the three control levels (Low, Mid, High) over multiple runs and days.
• Accuracy: Triplicate measurements for 9 different theoretical concentrations.
• Linearity: Triplicate measurements for 5 different theoretical concentrations.
• Sensitivity: Determined using standard deviation of duplicate determinations of the zero calibrator and the 1st non-zero calibrator (Cal B, 5µg/mL).
• Specificity (CDP-I): Not explicitly stated, but implies a sufficient number of replicates to determine cross-reactivity percentage at a specified concentration.
• Interferences (Endogenous): Triplicate measurements for each of the 8 interfering substances tested.
• Interferences (HAMA): Triplicate measurements for HAMA Type-1, HAMA Type-2, and their respective controls.
• Interferences (Co-Administered Drugs): Not explicitly stated for each drug, but for all 44 drugs, measured at 500 µg/mL in a vancomycin spiked serum pool at 25 µg/mL, compared to a control serum.
• Interferences (Structurally Related Drug - Teicoplanin): Not explicitly stated, but implies sufficient measurements at 4 different teicoplanin concentrations.
• Method Comparison: 146 serum samples from patients.

Data Provenance: The document does not explicitly state the country of origin for any data or whether the studies were retrospective or prospective, beyond stating "human serum or plasma" for the intended use and "patient serum samples" for method comparison. Given the context of a 510(k) submission in the US, it's likely conducted or overseen in the US.

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

This device is an in-vitro diagnostic assay for measuring vancomycin concentration. The "ground truth" for the test set (e.g., actual vancomycin concentrations, absence/presence of interfering substances) would be established by the precise formulation of controls, calibrators, spiked samples, and highly accurate reference methods or laboratory standards, rather than expert human interpretation. For the method comparison study, the "ground truth" for the patient samples was established by the predicate device, the Abbott TDx® Vancomycin assay. Therefore, the concept of "experts establishing ground truth" in the typical sense of radiologists or pathologists is not directly applicable here.

4. Adjudication Method for the Test Set

Adjudication methods (like 2+1 or 3+1) are typically used in studies involving subjective interpretation of medical images or clinical data where human readers might disagree. For an in-vitro diagnostic device that provides quantitative measurements, the "adjudication" is inherent in the analytical methods used to establish reference values (e.g., highly pure reference materials, established laboratory protocols, or a predicate device). No human expert adjudication was involved in generating the values used as "ground truth" for the performance studies presented.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No Multi-Reader Multi-Case (MRMC) comparative effectiveness study was mentioned. This type of study is designed to evaluate the impact of a new diagnostic tool on decisions or performance of human readers, typically in image interpretation. This is not relevant for a quantitative laboratory assay like QMS® Vancomycin, which provides a numerical output for drug concentration.

6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study

Yes, the studies presented are all standalone performance evaluations of the QMS® Vancomycin assay. The device directly measures vancomycin concentration in a sample, and the performance characteristics (precision, accuracy, sensitivity, specificity, interference, method comparison) are assessed based solely on its own analytical output. There is no "human-in-the-loop" interaction in the immediate result generation for a quantitative assay of this nature.

7. Type of Ground Truth Used

The ground truth used for various studies includes:

• Precision: Defined concentrations of vancomycin in control materials.
• Accuracy (Recovery): Known theoretical concentrations of USP traceable vancomycin spiked into human serum.
• Linearity (Dilution): Known theoretical concentrations of vancomycin prepared by dilution.
• Sensitivity: Relies on the statistical properties of measurements of a zero calibrator and a known low-concentration calibrator (Cal B at 5 µg/mL).
• Specificity & Interferences: Known concentrations of vancomycin, the metabolite CDP-I, various endogenous substances, HAMA, co-administered drugs, and teicoplanin, either alone or spiked into vancomycin-containing serum.
• Method Comparison: Results obtained from the predicate device, the Abbott TDx® Vancomycin assay, used as the reference method for patient serum samples.

8. Sample Size for the Training Set

The document does not explicitly mention a "training set" in the context of device development. For an immunoassay like QMS® Vancomycin, the development typically involves extensive characterization of reagents, optimization of assay parameters, and formulation of calibrators and controls. This process would involve numerous experiments and data points before the final performance studies (summarized here) are conducted to demonstrate suitability for market clearance. The data provided focuses solely on the validation/test performance of the finalized device.

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

As noted above, a formal "training set" as understood in machine learning (where an algorithm learns from data with established ground truth) is not directly applicable to the development of a homogeneous particle-enhanced turbidimetric immunoassay. Instead, the "ground truth" during development would be established through:

• Chemical and biological characterization of reagents: Ensuring the quality and specificity of antibodies and microparticles.
• Use of highly purified vancomycin standards (e.g., USP traceable): To prepare calibrators and to spike samples for recovery and linearity studies.
• Reference laboratory methods: Potentially used during early development to confirm the accuracy of initial assay designs or to validate the content of control materials.
• Industry standards and guidelines: Extensive experimentation guided by principles for developing accurate and precise quantitative immunoassays.

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