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510(k) Data Aggregation
(284 days)
VITEK 2 YEAST VORICONAZOLE
VITEK® 2 Yeast Voriconazole is designed for antifungal susceptibility testing of Candida species. VITEK 2 Yeast Voriconazole is a quantitative test intended for use with the VITEK 2 and VITEK 2 Compact Systems as a laboratory aid in the determination of in vitro susceptibility to antifungal agents. Voriconazole has been shown to be active against most strains of the following microorganisms listed below according to the FDA label for the antifungal.
Active in vitro and in clinical infections Candida albicans Candida krusei Candida parapsilosis Candida tropicalis
Active in vitro but their clinical significance is uknown: Candida lusitaniae Candida guilliermondii
The VITEK 2 Antimicrobial Susceptibility Test (AST) is intended to be used with the VITEK® 2 System for the automated quantitative or qualitative susceptibility testing of isolated colonies for the most clinically significant aerobic gram-negative bacilli, Staphylococcus spp., Enterococcus spp., Streptococcus agalactiae, S. pneumoniae and clinically significant yeast.
The antifungal presented in VITEK 2 AST Cards is in concentrations equivalent by efficacy to standard method concentrations in mcg/ml. The VITEK 2 AST Cards are essentially miniaturized versions of the doubling dilution technique for determining the minimum inhibitory concentration (MIC) microdilution methodology.
The isolate to be tested is diluted to a standardized concentration in 0.45% saline before being used to rehydrate the antifungal medium within the card. The VITEK® 2 automatically fills, seals and places the card into the incubator/reader. The VITEK® 2 Compact has a manual filling and sealing operation. The VITEK® 2 monitors the growth of each well in the card over a defined period of time (up to 36 hours for yeast). At the completion of the incubation cycle, a report is generated that contains the MIC value along with the interpretive category result for each antifungal contained on the card.
This report describes the acceptance criteria and study proving the VITEK® 2 Yeast Voriconazole device meets these criteria.
1. Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Target) | Reported Device Performance |
|---|---|
| Essential Agreement (EA) with CLSI reference method incubated for 24 hrs. (Not explicitly stated as a numerical target, but implied to be high for "acceptable performance") | 99.2% Overall Essential Agreement |
| Category Agreement (CA) with CLSI reference method incubated for 24 hrs. (Not explicitly stated as a numerical target, but implied to be high for "acceptable performance") | 99.2% Overall Category Agreement |
| Essential Agreement (EA) with CLSI reference method incubated for 48 hrs. (Not explicitly stated as a numerical target, but implied to be high for "acceptable performance") | 96.9% Overall Essential Agreement |
| Category Agreement (CA) with CLSI reference method incubated for 48 hrs. (Not explicitly stated as a numerical target, but implied to be high for "acceptable performance") | 98.7% Overall Category Agreement |
| Reproducibility | Acceptable |
| Quality Control | Acceptable |
2. Sample Size Used for the Test Set and Data Provenance
The document states "An external evaluation was conducted with fresh and stock clinical isolates and stock challenge strains." However, the exact sample size (number of isolates) for the test set is not explicitly provided in the furnished text.
The data provenance is not explicitly stated in terms of country of origin, but it is implied to be from an "external evaluation," generally suggesting data collected in a clinical or laboratory setting. The use of "fresh and stock clinical isolates" indicates a mix of prospective (fresh clinical isolates) and retrospective (stock clinical isolates and challenge strains) data.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
The document does not mention the use of experts to establish ground truth. Instead, the ground truth was established by comparing the device's performance against a "CLSI reference method." This method would involve standardized laboratory procedures rather than expert consensus on individual cases.
4. Adjudication Method for the Test Set
Since the ground truth was established by the CLSI reference method, there was no adjudication method involving multiple human readers as would be typical in medical imaging or interpretation studies. The comparison was directly against the results generated by the reference method.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not performed. This type of study typically evaluates human reader performance with and without AI assistance, which is not applicable to an automated antimicrobial susceptibility test (AST) system.
6. Standalone Performance Study
Yes, a standalone performance study was done. The entire study described evaluates the VITEK® 2 Yeast Voriconazole device as a standalone algorithm (automated system) without human intervention in the interpretation process once the card is processed. The performance metrics (Essential Agreement and Category Agreement) directly reflect the algorithm's accuracy compared to the reference method.
7. Type of Ground Truth Used
The type of ground truth used was the CLSI reference method (Clinical and Laboratory Standards Institute). This is a standardized laboratory methodology for determining antimicrobial susceptibility, considered the gold standard for AST systems.
8. Sample Size for the Training Set
The document does not provide information regarding a specific training set or its sample size. This implies that the device's development might have used a different type of underlying data or that the training data details are proprietary and not included in this summary. For biological assays, often historical data and laboratory standards guide algorithm development.
9. How the Ground Truth for the Training Set Was Established
Since a specific training set is not mentioned, the method for establishing its ground truth is also not provided.
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