(37 days)
The Directigen™ EZ RSV test is a rapid chromatographic immunoassay for the direct and qualitative detection of Respiratory Syncytial Virus (RSV) antigen in nasopharyngeal washes, nasopharyngeal aspirates, nasopharyngeal swabs and nasopharyngeal swab/washes from patients suspected of having a viral respiratory infection. This test is intended for in vitro diagnostic use to aid in the diagnosis of Respiratory Syncytial Virus (RSV) infections in neonatal and pediatric patients under the age of 20. It is recommended that negative test results be confirmed by cell culture.
The Directigen EZ RSV antigen detection test is a chromatographic assay to detect RSV antigens extracted from various specimens of symptomatic patients. The speed and workflow of the Directigen EZ RSV test make it applicable as a "STAT" RSV antigen detection test, providing rapid, relevant information to assist with antiviral intervention and other clinical or support decisions.
Here's an analysis of the provided text regarding the acceptance criteria and supporting study for the BD Directigen™ EZ RSV assay:
This 510(k) submission (K101514) is for a modification to an already legally marketed device, the BD Directigen™ EZ RSV assay (K022133). The modification is specifically the change of controls from liquid to dry swabs. Therefore, the studies presented focus on demonstrating that these new dry controls perform equivalently and are as stable as the previously approved liquid controls, rather than a full efficacy study of the assay itself.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Dry swabs controls must be comparable in stability to current liquid controls | Data to date from accelerated stability studies: indicated 30 months at 2-30°C. |
| Confirmatory real time stabilities: indicated 5 months at 2-30°C. (Real-time stability studies will continue.) | |
| Dry swabs controls must perform in the assay comparable to the current liquid controls | Dry swabs perform comparably in the assay to the current liquid controls. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not specify the exact sample sizes used for the stability and performance studies of the dry swab controls. It only states "Data to date from accelerated stability studies" and "Confirmatory real time stabilities" for stability, and "Dry swabs perform comparably in the assay" for performance.
Data Provenance: Not explicitly stated, but these are likely internal validation studies conducted by the manufacturer (Becton, Dickinson and Company). The document does not indicate country of origin for the data or if it's retrospective or prospective, though performance and stability studies are generally prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable in the context of this submission. The ground truth here is the established performance of the previous liquid controls and the expectation that the new dry controls should match that performance. There is no mention of external experts being used for this comparison.
4. Adjudication Method for the Test Set
Not applicable. This submission concerns the performance of controls, not diagnostic interpretations requiring adjudication.
5. If a Multi Reader Multi Case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
Not applicable. This device is a rapid chromatographic immunoassay, not an AI-powered diagnostic system, and it does not involve human readers interpreting results in a way that typically necessitates an MRMC study.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable. This is an in vitro diagnostic device, not an algorithm. The "standalone" performance here refers to the device's ability to accurately detect the RSV antigen using the new controls in laboratory settings, which is what the performance studies aimed to demonstrate.
7. The Type of Ground Truth Used
The ground truth used for these studies is the performance characteristics of the legally marketed predicate device's liquid controls. The goal was to establish that the new dry controls yield equivalent or better results (in terms of stability and assay performance) compared to the established liquid controls.
8. The Sample Size for the Training Set
Not applicable. This is an in vitro diagnostic assay with modified controls, not a machine learning algorithm requiring a "training set" in the conventional sense. The "training" for the device would have implicitly happened during its original development (K022133), but this document focuses on the validation of the control modification.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there isn't a "training set" for an algorithm. For the original assay's development, the ground truth would have been established through a combination of clinical samples confirmed by a gold standard method (e.g., cell culture for RSV detection). However, this information is not part of this specific 510(k) submission which only addresses the control modification.
§ 866.3480 Respiratory syncytial virus serological reagents.
(a)
Identification. Respiratory syncytial virus serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to respiratory syncytial virus in serum. Additionally, some of these reagents consist of respiratory syncytial virus antisera conjugated with a fluorescent dye (immunofluorescent reagents) and used to identify respiratory syncytial viruses from clinical specimens or from tissue culture isolates derived from clinical specimens. The identification aids in the diagnosis of respiratory syncytial virus infections and provides epidemiological information on diseases caused by these viruses. Respiratory syncytial viruses cause a number of respiratory tract infections, including the common cold, pharyngitis, and infantile bronchopneumonia.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 866.9.