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ACE® Valproic Acid Reagent is intended for use in the quantitative determination of valproic acid in human serum.
ACE® Valproic Acid Reagent is intended for the quantitative determination of valproic acid in serum using the ACE® clinical chemistry analyzer.

The ACE® Valproic Acid Reagent contains two reagents, an Antibody/Substrate reagent and an Enzyme Conjugate reagent. The assay uses specific antibodies to valproic acid and is based on the competition of an enzyme glucose-6-phosphate dehydrogenase (G6PDH) labeled drug and the free drug from the sample, for a fixed amount of specific antibody binding sites. In the absence of free drug from the sample, the drug-labeled G6PDH is bound by the specific antibody and the enzyme activity is inhibited. This phenomenon creates a relationship between drug concentration in the sample and the enzyme activity. The enzyme G6PDH activity is determined bichromatically on the ACE® at 340/505 nm by measuring its ability to convert NAD* to NADH.

The ACE® Valproic Acid Reagent is an enzyme immunoassay intended for the quantitative determination of valproic acid in human serum. The study demonstrated its substantial equivalence to a predicate device, the DRI Valproic Acid Enzyme Immunoassay, based on performance parameters such as assay range, precision, and correlation with another commercial valproic acid assay.

Here's a breakdown of the requested information:

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are implicitly defined by demonstrating substantial equivalence to the predicate device and showing comparable performance. The performance metrics of the predicate device serve as the de facto acceptance criteria.

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

The document provides the sample sizes for the correlation studies:

• For the correlation against the "Commercial valproic acid assay" (predicate device's correlation), the sample size (N) was 88.
• For the proposed device's correlation against the "Hitachi 717" analyzer, the sample size (N) was 49.

The data provenance (country of origin, retrospective/prospective) is not explicitly stated in the provided summary. However, given that this is a 510(k) submission to the FDA in the United States, it is highly probable the data was generated in the US. The nature of "method correlation" and "within-run and between-run precision" studies typically involves prospective laboratory testing using patient samples or control materials.

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

This type of information is not applicable for this device and study. The device is a quantitative diagnostic reagent, where the "ground truth" for method correlation is typically established by comparative measurements against a well-characterized reference method or an existing, clinically accepted method (like the Hitachi 717 or the "Commercial valproic acid assay"). This does not involve expert consensus in the same way an imaging or diagnostic AI device does.

4. Adjudication Method for the Test Set

Not applicable for this type of quantitative diagnostic device. Adjudication methods like 2+1 or 3+1 are typically used for assessing qualitative or semi-quantitative results, often involving human interpretation of images or clinical findings, which is not the case here.

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

No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This type of study design is relevant for AI-powered diagnostic tools that assist human interpreters (e.g., radiologists, pathologists). The ACE® Valproic Acid Reagent is a standalone quantitative assay and does not involve human interpretation in the same manner.

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

Yes, a standalone performance assessment was conducted. The "Performance Summary" and "Correlation" data presented are for the device's performance as an algorithm only (reagent on an analyzer), without human-in-the-loop performance influencing the quantitative measurement of valproic acid.

7. The Type of Ground Truth Used (Expert Consensus, Pathology, Outcomes Data, etc.)

The ground truth for the performance assessment was established by comparison against established, commercially available methods that are presumed to be accurate and clinically accepted. Specifically:

• The predicate device's performance (used as a benchmark) was shown in correlation against a "Commercial valproic acid assay."
• The proposed device's performance was shown in correlation against a "Hitachi 717" analyzer.

These methods themselves serve as the "ground truth" for determining the accuracy and reliability of valproic acid measurements.

8. The Sample Size for the Training Set

The document does not explicitly mention a separate "training set" or its sample size. This is typical for a diagnostic reagent where the assay parameters are generally optimized during research and development, and the validation studies (precision, correlation) are akin to a "test set" for regulatory submission.

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

As no explicit training set is mentioned in the regulatory summary, information on how its "ground truth" was established is not provided. If an internal optimization process involved various samples, their "true" valproic acid concentrations would have been determined using highly reliable, possibly reference, methods.

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