(52 days)
To determine gram-negative bacterial susceptibility against the antimicrobial agent Sparfloxacin. Organisms with indications for testing* include: Gram-Negative Bacteria Enterobacter cloacae Klebsiella pneumoniae * As taken from the Indications and Usage section of the manufacturer's package insert (as provided by the Sparfloxacin manufacturer, Rhone Poulenc Rorer Pharmaceuticals).
Microdilution Minimum Inhibitory Concentration (MIC) Panel, MicroScan® Dried Gram-Negative MIC/Combo Panels
Here's an analysis of the provided text regarding the Dade MicroScan Inc. MicroScan Dried Gram-Negative MIC/Combo Panels with Sparfloxacin, addressing your specific points:
Acceptance Criteria and Study Details
The provided document describes a premarket notification for a new antimicrobial agent (Sparfloxacin) on an existing device. The acceptance criteria for such devices typically revolve around demonstrating substantial equivalence to a predicate device, as defined by FDA guidelines.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Derived) | Reported Device Performance |
|---|---|
| Overall Essential Agreement with NCCLS frozen Sparfloxacin Reference Panel should be acceptable. | 99.1% Overall Essential Agreement |
| Acceptable reproducibility and precision across different inoculum methods and instruments. | Demonstrated acceptable reproducibility and precision. |
| Acceptable Quality Control performance. | Quality Control performance was acceptable. |
Note: The document refers to the "FDA DRAFT document 'Review Criteria for Assessment of Antimicrobial Susceptibility Devices' (dated May 31, 1991)" for the definition of "substantially equivalent performance." Without this specific draft document, the exact numerical acceptance criteria for "acceptable" are not explicitly stated within the provided text. However, the reported 99.1% Essential Agreement is presented as meeting this "acceptable performance."
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The document does not explicitly state the numerical sample size for the test set (number of isolates/strains tested). It mentions that "external evaluations were conducted with fresh and stock Efficacy isolates and stock Challenge strains."
- Data Provenance: The data provenance is not explicitly stated in terms of country of origin. The study appears to be retrospective in nature using "stock" strains, and potentially prospective for "fresh Efficacy isolates."
3. Number of Experts Used to Establish Ground Truth and Qualifications
This information is not provided in the document. The ground truth for antimicrobial susceptibility testing is typically established using a recognized reference method (in this case, an NCCLS frozen Sparfloxacin Reference Panel), not by expert consensus interpreting images or clinical data.
4. Adjudication Method for the Test Set
The concept of "adjudication method" (e.g., 2+1, 3+1) is not applicable here. This is typically used in studies involving human interpretation of clinical data or images. In this context, the comparison is directly between the result from the MicroScan panel and the result from the NCCLS reference panel. Any discrepancies would likely be resolved by re-testing or review of the raw data, rather than expert adjudication in the traditional sense.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
An MRMC study was not conducted. This type of study is relevant for devices that involve human interpretation of medical images or clinical data, where the performance of human readers with and without AI assistance is being evaluated. This device is an automated in vitro diagnostic for antimicrobial susceptibility, not an image analysis or clinical decision support AI.
6. Standalone (Algorithm Only) Performance
The study primarily evaluates the standalone performance of the device (MicroScan panel) compared to the reference method (NCCLS frozen panel). The outcome is the "Essential Agreement" between the device's reading and the ground truth. There is no human-in-the-loop component being assessed in terms of interpretation or decision-making for susceptibility results.
7. Type of Ground Truth Used
The type of ground truth used is a reference method standard. Specifically, the "NCCLS frozen Sparfloxacin Reference Panel" served as the gold standard against which the performance of the MicroScan Dried Gram-Negative MIC/Combo Panels with Sparfloxacin was measured.
8. Sample Size for the Training Set
The document does not report a sample size for a training set. This is consistent with the nature of the device. This is not a machine learning or AI algorithm in the contemporary sense that would require a distinct "training set" to develop its internal logic. The device's mechanism for determining MIC values is based on established biochemical reactions and readouts, not on learning from a large dataset. The "external evaluations" described are for validation, not training.
9. How Ground Truth for the Training Set Was Established
Since there is no reported training set in the context of machine learning, the question of how its ground truth was established is not applicable. The device's underlying principles are based on microbiological and chemical assays, and its accuracy is validated against a recognized reference standard rather than being "trained" on a dataset with pre-established ground truth.
§ 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).