(85 days)
Pasco MIC and MIC/ID panels are used for quantitatively measuring (with the exception of the Breakpoint/ID panel which provides qualitative measurement of category results) the susceptibility of rapidly growing aerobic and facultative anaerobic bacterial pathogens to a battery of antimicrobial agents and determining the biochemical identification of those organisms.
This 510(k) notification is for the addition of Cefepime to Pasco panels at concentrations of 0.03 to 64 mcg/ml for use in determining the susceptibility of Enterobacter spp., E. col, K. pneumoniae, P. mirabilis, P. aeruginosa and methicillin susceptible strains of S. aureus. Clinical testing of S. pneumoniae has not been performed with the Pasco system.
Varying concentrations of antimicrobial agents (usually in twofold dilutions) are dispensed into the Pasco panels and the panels are then frozen. Panels are thawed prior to use, inoculated with the test organisms, incubated the traditional 16-24 hours and then observed for visible growth or color changes as described in the package insert.
The lowest concentration of each antimicrobial agent with no apparent visible growth of the test organism is recorded as the minimum inhibitory concentration (MIC). Changes in pH and production of specific metabolites from growth in biochemical substrates are interpreted as described in the package insert for conventional tubed media.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Device Name: Pasco MIC and MIC/ID Panels (with the addition of Cefepime)
Device Type: Antimicrobial Susceptibility Test
1. Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria | Reported Device Performance (Gram-Negative Isolates) | Reported Device Performance (Gram-Positive Isolates) |
|---|---|---|
| Essential Agreement (EA) | Initial: 98.2% | |
| Retest: 99.4% | Initial: 100% | |
| Very Major (VM) Error | 1 VM error on initial testing (Klebsiella pneumoniae), resolved upon retest | None observed |
| Category Agreement (CA) | 97.3% (9 random minor errors) | 88.1% (29 random minor errors) |
| Major Errors | Not explicitly stated for Gram-negative, but implied acceptable given overall performance and no mention of significant major errors. | None observed |
| QC Endpoints within Recommended Ranges | Yes (reference and Pasco panels) | Yes (reference and Pasco panels) |
| Reproducibility (within +/- 1 dilution) | 98.8% | 98.8% (assuming this applies to both) |
2. Sample Size and Data Provenance:
- Test Set Sample Size: Not explicitly stated as a numerical value for patients or isolates. The text mentions "CDC challenge strains and clinical isolates."
- For Gram-negative isolates: Performance is described for specific organisms like Enterobacter spp., E. coli, K. pneumoniae, P. mirabilis, and P. aeruginosa.
- For Gram-positive isolates: Performance is described for methicillin-susceptible strains of S. aureus.
- Data Provenance: The study was performed at "two sites." The country of origin is not specified, but given the context of a 510(k) summary submitted to the FDA, it is highly likely to be the United States. The study used "CDC challenge strains and clinical isolates," indicating a prospective collection of isolates for comparative testing.
3. Number of Experts and Qualifications:
- Number of Experts: Not specified.
- Qualifications of Experts: Not specified. It's implied that "comparative testing" against a "reference panel" was performed, which usually involves trained microbiologists or laboratory personnel, but their specific qualifications or experience levels are not detailed.
4. Adjudication Method:
- Adjudication Method: Not explicitly stated. The text mentions "resolved upon retest" for the single Very Major error, suggesting some form of re-evaluation or confirmatory testing. However, a formal adjudication process (like 2+1 or 3+1 by independent experts) for discordant results is not described.
5. Multi Reader Multi Case (MRMC) Comparative Effectiveness Study:
- MRMC Study: No. This study is evaluating the performance of an in vitro diagnostic device (antimicrobial susceptibility panel) against a reference method, not the effectiveness of AI assistance on human readers. Therefore, an MRMC study and effect size of human readers with/without AI assistance are not applicable.
6. Standalone (Algorithm Only) Performance:
- Standalone Performance: Not applicable in the context of an in vitro diagnostic device like an antimicrobial susceptibility panel. The device itself is the "standalone" component being tested against a reference standard. There isn't an "algorithm" being evaluated independently of its human-in-the-loop application in the same way as an AI-powered image analysis tool. The results presented are the performance of the Pasco panels themselves.
7. Type of Ground Truth Used:
- Ground Truth: The ground truth was established by a reference panel or reference method. The text states, "Comparative testing of the Pasco test panel to a reference panel was performed." This implies that the results from the established reference method were considered the true susceptibility results against which the Pasco panel's performance was measured.
8. Sample Size for the Training Set:
- Training Set Sample Size: Not applicable. This document describes a clinical validation study for a medical device (an in-vitro diagnostic panel), not a machine learning model. The device itself is a physical laboratory test, not a software algorithm that requires a "training set" in the machine learning sense. The "training" for such devices typically involves manufacturing controls and calibration processes, not data ingestion for model optimization.
9. How Ground Truth for the Training Set Was Established:
- Ground Truth for Training Set: Not applicable, as there is no "training set" in the context of a machine learning model. The development of the Pasco panels would have involved standard microbiological and manufacturing quality control procedures to ensure the accuracy of the antimicrobial concentrations and reagents.
§ 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).