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For in vitro diagnostic use:

Etest is a quantitative technique for the determination of antimicrobial susceptibility of both non-fastidious Gram negative and Gram positive aerobic bacteria, such as Enterobacteriaceae, Pseudomonas, Staphylococcus and Enterococcus species and fastidious bacteria, such as anaerobes, Pneumococcus and Haemophilus species. The system comprises a predefined antibiotic gradient which is used to determine the Minimum Inhibitory Concentration (MIC) in ug/ml of individual antibiotics against bacteria as tested on agar media by overnight incubation.

This Etest 510(k) application is for MIC determination of Tetracycline in the range of 0.016 - 256 µg/ml with non-fastidious Gram positive and Gram negative aerobic bacteria, H. influenzae, N. gonorrhoeae and Streptococcus spp.

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Here's an analysis of the provided text regarding the Etest® Tetracycline device, extracting information relevant to acceptance criteria and the supporting study, while noting what information is not present in these specific documents.

It's important to understand that the provided text is an FDA 510(k) clearance letter and an "Indications For Use" statement. These documents do not typically contain detailed study designs, acceptance criteria tables, or comprehensive performance data. They refer to a study that was submitted to the FDA, but the details of that study are not explicitly included here.

Therefore, many of your requested points will be answered as "Not explicitly stated in the provided text."

Acceptance Criteria and Device Performance Study Information for Etest® Tetracycline

Given the provided text, a comprehensive description of acceptance criteria and the full study results is not available. The documents are an FDA clearance letter and the "Indications For Use" statement, which refer to a study that was submitted as part of the 510(k) application (K981134). The specific details of that study are not included in these excerpts.

However, based on the information provided, we can infer some aspects and highlight what is missing.

1. Table of Acceptance Criteria and Reported Device Performance

Note: The provided FDA letter states "we have determined the device is substantially equivalent... to legally marketed predicate devices." This implies that the performance data submitted for Etest® Tetracycline met the FDA's criteria to demonstrate equivalence to existing, legally marketed Tetracycline susceptibility tests, likely by achieving agreement rates (Essential Agreement, Category Agreement, and acceptable discrepancy rates) similar to or better than previously cleared devices.

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

• Sample Size for Test Set: Not explicitly stated in the provided documents.
• Data Provenance: Not explicitly stated (e e.g., country of origin, retrospective or prospective). However, clinical studies for medical devices are typically prospective, but retrospective data can also be used for certain aspects.

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

• Number of Experts: Not explicitly stated.
• Qualifications of Experts: Not explicitly stated. For antimicrobial susceptibility testing, the "ground truth" (reference method results) is typically established by trained microbiologists following standardized laboratory procedures (e.g., NCCLS/CLSI guidelines) for a well-characterized reference MIC method (e.g., broth microdilution or agar dilution).

4. Adjudication Method for the Test Set

• Adjudication Method: Not applicable or explicitly stated. For MIC determination, the reference method provides a quantitative result. Discrepancies are usually analyzed against this reference, rather than adjudicated by multiple human readers in the same way imaging studies might be.

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

• MRMC Study Done: No, an MRMC study is not typically applicable for automated/semi-automated in vitro diagnostic devices like Etest for MIC determination. MRMC studies are common for diagnostic imaging AI systems where human readers interpret images with and without AI assistance. The Etest directly provides an MIC result, reducing the variability associated with human interpretation.
• Effect Size of Human Readers with/without AI Assistance: Not applicable.

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

• Standalone Study Done: Yes, implicitly. The performance data submitted for Etest® Tetracycline would represent its "standalone" performance against a reference method. Etest itself is a device that produces a result (MIC) which is then interpreted by a trained microbiologist. The "algorithm" here is the physical gradient strip and the chemical properties that produce the elliptical inhibition zone, which is then measured. The evaluation would be on how accurately this method determines the MIC compared to a gold standard.

7. Type of Ground Truth Used

• Type of Ground Truth: The ground truth for antimicrobial susceptibility testing is typically established by a reference Minimum Inhibitory Concentration (MIC) method, such as broth microdilution or agar dilution, performed according to recognized standards (e.g., National Committee for Clinical Laboratory Standards [NCCLS], now Clinical and Laboratory Standards Institute [CLSI]). This is considered the "gold standard" for determining the susceptibility of bacteria to antibiotics.

8. Sample Size for the Training Set

• Sample Size for Training Set: Not explicitly stated. Etest is a phenotypic test, not an AI/ML algorithm in the modern sense that requires a "training set" of data in the same way. Its design is based on established principles of antibiotic diffusion. However, internal development and optimization of the strip's gradient would involve extensive testing. If "training set" refers to the initial validation data used during product development (prior to the submission of the Pivotal/Confirmatory study), that information is not present.

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

• How Ground Truth for Training Set Was Established: Not applicable in the context of an AI/ML "training set" for Etest. If "training set" refers to the development phase, the ground truth would have been established using the same reference MIC methods as described in point 7.

Summary of Missing Information:

The provided documents, being a 510(k) clearance letter and an "Indications For Use" statement, primarily confirm the device's clearance and intended use. They do not contain the detailed study report that would specify:

• The exact sample sizes for testing.
• The raw performance data (Essential Agreement, Category Agreement, discrepancy rates).
• Details of the specific reference methods used.
• The data provenance (e.g., country, study centers).
• Any specifics about the development process or validation prior to the pivotal submission study.

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For in vitro diagnostic use:

Etest is a quantitative technique for the determination of antimicrobial susceptibility of both non-fastidious Gram negative and Gram positive aerobic bacteria, such as Enterobacteriaceae, Pseudomonas, Staphylococcus and Enterococcus species and fastidious bacteria, such as anaerobes, Pneumococcus and Haemophilus species. The system comprises a predefined antibiotic gradient which is used to determine the Minimum Inhibitory Concentration (MIC) in ug/ml of individual antibiotics against bacteria as tested on agar media by overnight incubation.

This application is for MIC determination of Tetracycline in the range of 0.016 - 256 µg/ml with Streptococcus spp.

Previously cleared applications include non-fastidious Gram positive and Gram negative aerobic bacteria, H. influenzae and S. pneumoniae.

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While the provided text describes the regulatory approval of the Etest® Tetracycline for determining antimicrobial susceptibility, it does not contain the detailed clinical study information and acceptance criteria typically found in a clinical trial report or a comprehensive technical document.

Therefore, I cannot provide a table of acceptance criteria and reported device performance or information regarding specific study parameters like sample size, data provenance, expert involvement, or ground truth details.

However, based on the context of the 510(k) submission, I can infer some general information about the type of study that would have been conducted and the nature of the acceptance criteria.

Inferred Information based on 510(k) Approval for an In Vitro Diagnostic Device:

For a device like the Etest® Tetracycline, which determines Minimum Inhibitory Concentration (MIC), the acceptance criteria and study would typically involve:

• Comparison to a "Gold Standard" Reference Method: The primary study would compare the Etest's MIC results against an established, validated reference method (e.g., broth microdilution or agar dilution as defined by CLSI/NCCLS standards at the time).
• Accuracy Metrics: Acceptance criteria would likely involve:
  • Essential Agreement (EA): The percentage of MIC values that are within ±1 (or sometimes ±2) doubling dilutions of the reference method.
  • Categorical Agreement (CA): The percentage of isolates where the Etest and the reference method agree on the susceptibility categorization (e.g., Susceptible, Intermediate, Resistant) based on established breakpoints.
  • Major Discrepancies (MD): Instances where the Etest indicates susceptible and the reference indicates resistant.
  • Very Major Discrepancies (VMD): Instances where the Etest indicates resistant and the reference indicates susceptible.
• Reproducibility/Precision: Studies demonstrating consistent results when the test is performed multiple times on the same isolate under similar conditions (within-laboratory and between-laboratory).

Specific Information NOT Present in the Provided Text:

All of the following information is not available in the provided document:

1. Table of Acceptance Criteria and Reported Device Performance: This document is a regulatory approval letter, not a study report. It states that the device is "substantially equivalent," implying that a study was done and met criteria, but it does not detail those criteria or the performance metrics.
2. Sample size used for the test set and the data provenance: No numerical data on sample size, country of origin, or retrospective/prospective nature of the study is given.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not mentioned. For microbiology, the "ground truth" would typically be derived from the reference method, not human expert interpretation of the test itself.
4. Adjudication method: Not applicable as the "ground truth" is typically the reference method's result.
5. Multi-reader multi-case (MRMC) comparative effectiveness study: This is not relevant for an in vitro diagnostic device like Etest, which provides a quantitative result (MIC). MRMC studies are typically for imaging or interpretive diagnostics where human readers analyze data.
6. Standalone performance (algorithm only): The Etest is a physical strip. Its "performance" is inherently based on the chemical reaction and visual interpretation of the ellipse formation. There isn't an "algorithm only" performance in the traditional sense of AI.
7. Type of ground truth used: While not explicitly stated, for an antimicrobial susceptibility test, the ground truth would be the results obtained from a recognized reference method (e.g., CLSI/NCCLS standard broth microdilution or agar dilution).
8. Sample size for the training set: Not applicable; the Etest is not an AI/ML device that requires a "training set" in the computational sense.
9. How the ground truth for the training set was established: Not applicable.

Summary of what the document DOES tell us:

• Device Name: Etest® Tetracycline
• Indications For Use: Quantitative determination of Tetracycline MIC (0.016 - 256 µg/ml) for Streptococcus spp. It also mentions previous clearance for other bacteria.
• Regulatory Status: Cleared via 510(k) as substantially equivalent to a predicate device.
• Device Type: In vitro diagnostic device.

To obtain the detailed study information, one would typically need to consult the original 510(k) submission document (if publicly available in full detail), the device's labeling (package insert), or peer-reviewed publications validating the Etest device.

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