(51 days)
SAS™ Influenza B Test is a visual and rapid assay for the presumptive qualitative detection of Influenza Type B antigens from nasal washes and aspirates. Negative results should be confirmed via culture. This test is not intended for the detection of Influenza Type A or C viral antigen. The test is for professional use.
The SAS™ Influenza B test utilizes a set monoclonal antibodies against Influenza Type B viral nucleoproteins. The SAS™ Influenza test begins with an extraction of Type B nucleoproteins. After the extraction has been completed, the sample is placed into the test and observed for the formation of colored lines. The specimen is absorbed and migrates via capillary action through a membrane that contains dried gold conjugated antibody, which is specific for Influenza Type B nucleoproteins. If Type B nucleoproteins are present, a "half-sandwich" immuno-complex is formed. The membrane contains immobilized antibody to Influenza Type B nucleoproteins, which binds the "half sandwich" complex. Thus, in the presence of Influenza nucleoproteins, a "whole sandwich" immuno-complex is formed and a visible, pink colored line develops in the specimen zone of the test device. In the absence of an Influenza antigen, a "sandwich" immuno-complex is not formed and a negative result is indicated. To serve as a procedural control, a pink colored control line will always appear in the control zone regardless of the presence or absence of Influenza B nucleoproteins.
Acceptance Criteria and Study for SAS™ Influenza B Test
The provided document describes the SAS™ Influenza B Test, an immunoassay for the presumptive qualitative detection of Influenza Type B antigens. The primary study presented aims to demonstrate substantial equivalence to a predicate device, the Binax™ NOW® Flu B Test.
1. Table of Acceptance Criteria and Reported Device Performance
The submission does not explicitly state pre-defined acceptance criteria in terms of specific sensitivity, specificity, or positive/negative predictive values. Instead, the acceptance criterion appears to be demonstrating substantial equivalence to the predicate device. The performance summary indirectly addresses this by stating the device performed "substantially equivalent" when compared to the predicate using freshly collected nasal wash specimens.
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance Statement |
|---|---|---|
| Equivalence | Substantial equivalence to predicate device (Binax™ NOW® Flu B Test) | "The SAS™ Influenza B test performed substantially equivalent to the predicate device, Binax™ NOW® Flu B test." |
| Cross-Reactivity | No interference or cross-reaction with common respiratory viral and bacterial strains. | "None of the organisms interfered or cross-reacted with the performance of the SAS™ Influenza B test." |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: Not explicitly stated. The document indicates that the comparison was made using "freshly collected nasal wash specimens." The exact number of specimens is not provided.
- Data Provenance: The data is described as using "freshly collected nasal wash specimens," implying the data is prospective in nature. The country of origin is not specified, but the submission is from SA Scientific, Inc. in San Antonio, TX, USA, suggesting the data is likely from the United States.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not mention the use of experts to establish a "ground truth" for the test set in the traditional sense (e.g., expert consensus on images). Instead, the study's ground truth for comparison is likely derived from the predicate device's results, or potentially in conjunction with a more definitive method like viral culture, though culture is only mentioned for confirming negative results in the "Indications for Use."
4. Adjudication Method for the Test Set
No adjudication method is described. The study appears to be a direct comparison of the investigational device's results against the predicate device's results, or against a reference standard without mention of a formal adjudication process.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. The device is a rapid immunoassay test, which typically provides a single, objective result (positive/negative) without requiring interpretation by multiple readers. Therefore, the concept of human readers improving with or without AI assistance is not applicable to this type of device.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
Yes, a standalone performance study was done. The SAS™ Influenza B Test is a visual immunoassay that produces a direct result. Its performance is evaluated intrinsically through its ability to detect the target antigen, not as an algorithm assisting a human. The performance summary describes its direct comparison to the predicate device, indicating a standalone evaluation.
7. Type of Ground Truth Used
The primary ground truth for establishing substantial equivalence was likely the results from the predicate device (Binax™ NOW® Flu B Test) using the same "freshly collected nasal wash specimens." While the "Indications for Use" section states that "Negative results should be confirmed via culture," it's not explicitly stated that viral culture was used as the definitive ground truth for the equivalence study itself, but rather as a clinical follow-up for specific results.
8. Sample Size for the Training Set
The concept of a "training set" is not applicable as this is a rapid immunoassay device, not a machine learning or AI algorithm. Therefore, no training set size is mentioned.
9. How the Ground Truth for the Training Set Was Established
As there is no training set for this type of device, this question is not applicable.
§ 866.3328 Influenza virus antigen detection test system.
(a)
Identification. An influenza virus antigen detection test system is a device intended for the qualitative detection of influenza viral antigens directly from clinical specimens in patients with signs and symptoms of respiratory infection. The test aids in the diagnosis of influenza infection and provides epidemiological information on influenza. Due to the propensity of the virus to mutate, new strains emerge over time which may potentially affect the performance of these devices. Because influenza is highly contagious and may lead to an acute respiratory tract infection causing severe illness and even death, the accuracy of these devices has serious public health implications.(b)
Classification. Class II (special controls). The special controls for this device are:(1) The device's sensitivity and specificity performance characteristics or positive percent agreement and negative percent agreement, for each specimen type claimed in the intended use of the device, must meet one of the following two minimum clinical performance criteria:
(i) For devices evaluated as compared to an FDA-cleared nucleic acid based-test or other currently appropriate and FDA accepted comparator method other than correctly performed viral culture method:
(A) The positive percent agreement estimate for the device when testing for influenza A and influenza B must be at the point estimate of at least 80 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 70 percent.
(B) The negative percent agreement estimate for the device when testing for influenza A and influenza B must be at the point estimate of at least 95 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 90 percent.
(ii) For devices evaluated as compared to correctly performed viral culture method as the comparator method:
(A) The sensitivity estimate for the device when testing for influenza A must be at the point estimate of at least 90 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 80 percent. The sensitivity estimate for the device when testing for influenza B must be at the point estimate of at least 80 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 70 percent.
(B) The specificity estimate for the device when testing for influenza A and influenza B must be at the point estimate of at least 95 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 90 percent.
(2) When performing testing to demonstrate the device meets the requirements in paragraph (b)(1) of this section, a currently appropriate and FDA accepted comparator method must be used to establish assay performance in clinical studies.
(3) Annual analytical reactivity testing of the device must be performed with contemporary influenza strains. This annual analytical reactivity testing must meet the following criteria:
(i) The appropriate strains to be tested will be identified by FDA in consultation with the Centers for Disease Control and Prevention (CDC) and sourced from CDC or an FDA-designated source. If the annual strains are not available from CDC, FDA will identify an alternative source for obtaining the requisite strains.
(ii) The testing must be conducted according to a standardized protocol considered and determined by FDA to be acceptable and appropriate.
(iii) By July 31 of each calendar year, the results of the last 3 years of annual analytical reactivity testing must be included as part of the device's labeling. If a device has not been on the market long enough for 3 years of annual analytical reactivity testing to have been conducted since the device received marketing authorization from FDA, then the results of every annual analytical reactivity testing since the device received marketing authorization from FDA must be included. The results must be presented as part of the device's labeling in a tabular format, which includes the detailed information for each virus tested as described in the certificate of authentication, either by:
(A) Placing the results directly in the device's § 809.10(b) of this chapter compliant labeling that physically accompanies the device in a separate section of the labeling where the analytical reactivity testing data can be found; or
(B) In the device's label or in other labeling that physically accompanies the device, prominently providing a hyperlink to the manufacturer's public Web site where the analytical reactivity testing data can be found. The manufacturer's home page, as well as the primary part of the manufacturer's Web site that discusses the device, must provide a prominently placed hyperlink to the Web page containing this information and must allow unrestricted viewing access.
(4) If one of the actions listed at section 564(b)(1)(A)-(D) of the Federal Food, Drug, and Cosmetic Act occurs with respect to an influenza viral strain, or if the Secretary of Health and Human Services (HHS) determines, under section 319(a) of the Public Health Service Act, that a disease or disorder presents a public health emergency, or that a public health emergency otherwise exists, with respect to an influenza viral strain:
(i) Within 30 days from the date that FDA notifies manufacturers that characterized viral samples are available for test evaluation, the manufacturer must have testing performed on the device with those viral samples in accordance with a standardized protocol considered and determined by FDA to be acceptable and appropriate. The procedure and location of testing may depend on the nature of the emerging virus.
(ii) Within 60 days from the date that FDA notifies manufacturers that characterized viral samples are available for test evaluation and continuing until 3 years from that date, the results of the influenza emergency analytical reactivity testing, including the detailed information for the virus tested as described in the certificate of authentication, must be included as part of the device's labeling in a tabular format, either by:
(A) Placing the results directly in the device's § 809.10(b) of this chapter compliant labeling that physically accompanies the device in a separate section of the labeling where analytical reactivity testing data can be found, but separate from the annual analytical reactivity testing results; or
(B) In a section of the device's label or in other labeling that physically accompanies the device, prominently providing a hyperlink to the manufacturer's public Web site where the analytical reactivity testing data can be found. The manufacturer's home page, as well as the primary part of the manufacturer's Web site that discusses the device, must provide a prominently placed hyperlink to the Web page containing this information and must allow unrestricted viewing access.