(119 days)
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:
- 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.
- 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.
- 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.
- Adjudication method: Not applicable as the "ground truth" is typically the reference method's result.
- 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.
- 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.
- 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).
- 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.
- 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.
§ 866.1640 Antimicrobial susceptibility test powder.
(a)
Identification. An antimicrobial susceptibility test powder is a device that consists of an antimicrobial drug powder packaged in vials in specified amounts and intended for use in clinical laboratories for determining in vitro susceptibility of bacterial pathogens to these therapeutic agents. Test results are used to determine the antimicrobial agent of choice in the treatment of bacterial diseases.(b)
Classification. Class II (performance standards).