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To determine antimicrobial agent susceptibility

MicroScan Dried Gram-Negative MIC/Combo Panels are designed for use in determining quantitative and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of rapidly growing aerobic and facultative anaerobic gram-neqative bacilli. The antimicrobial susceptibility tests are miniaturizations of the broth dilution susceptibility test that have been diluted in broth and dehydrated. Various antimicrobial agents are diluted in broth to concentrations bridging the range of clinical interest. Panels are rehydrated with water after inoculation with a standardized suspension of the organism. After incubation in a non-CO2 incubator for 16-20 hours, the minimum inhibitory concentration (MIC) for the test organism is read by determining the lowest antimicrobial concentration showing inhibition of growth.

Here's an analysis of the acceptance criteria and study detailed in the provided text:

Acceptance Criteria and Device Performance

1. Table of Acceptance Criteria and Reported Device Performance:

Note: The document states that the device demonstrated "substantially equivalent performance when compared with a CLSI frozen Reference Panel, as defined in the FDA document 'Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA', dated August 28, 2009." This FDA guidance document would contain the explicit, quantitative acceptance criteria for Essential Agreement, which the 96.8% met.

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

• Sample Size: The exact number of isolates used in the external evaluations is not explicitly stated. However, the text mentions "fresh, recent and stock Efficacy isolates and stock Challenge strains."
• Data Provenance: The data was collected from "external evaluations." The country of origin is not specified, nor is whether the data was retrospective or prospective. Given the nature of an antimicrobial susceptibility test, it's highly likely to involve prospective testing of isolates.

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

• Number of Experts: This information is not provided in the document for the establishment of the ground truth.
• Qualifications of Experts: This information is not provided in the document.

4. Adjudication Method for the Test Set:

• The document does not describe an adjudication method for establishing the ground truth. The comparison is made against a "CLSI frozen Reference Panel," which inherently serves as the reference standard. This suggests that the reference panel itself is the gold standard, rather than a process of expert adjudication for each test.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done:

• No, an MRMC comparative effectiveness study was not done. The study focuses on the performance of the automated device (MicroScan Dried Gram-Negative MIC/Combo Panels) against a reference standard (CLSI frozen Reference Panel), not on comparing human readers with and without AI assistance. The text explicitly refers to "MicroScan Dried Gram-Negative MIC/Combo Panels" as the "proposed" device, indicating it's an automated system.

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

• Yes, a standalone study was performed. The study assessed the performance of the "MicroScan Dried Gram-Negative MIC/Combo Panels" in determining Minimum Inhibitory Concentrations (MICs). This panel is an automated device designed to yield results without human intervention in the interpretation of the MICs. The comparison is against a CLSI reference panel, which is the standard for standalone device evaluation.

7. The Type of Ground Truth Used:

• CLSI Frozen Reference Panel. The ground truth was established by a "CLSI frozen Reference Panel." The Clinical and Laboratory Standards Institute (CLSI) sets the gold standard for antimicrobial susceptibility testing, and their reference panels are widely accepted as reliable ground truth in this field.

8. The Sample Size for the Training Set:

• Not Applicable / Not Provided. The document describes a performance evaluation of a device, not the development or training of an AI algorithm in the traditional sense. Therefore, there is no mention of a "training set" for an AI model. This device is a pre-programmed diagnostic tool, not a machine learning model that requires a training phase.

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

• Not Applicable / Not Provided. As there is no mention of a training set for an AI algorithm, the method for establishing its ground truth is not relevant to this document.

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