(30 days)
The Binax Strep A Test is intended for in vitro diagnostic use in clinical and physician office laboratories to qualitatively detect the presence of Streptococcus pyoqenes Group A antigen from throat swabs. The indication statements are the same as those made for the predicate devices.
The Binax Strep A Test is an immunochromatographic membrane assay to detect Streptococcus pyogenes Group A antigen from throat swabs. A test strip, containing gold-conjugated and immobilized anti-Strep A antibodies, and a swab well are mounted on opposite sides of a cardboard, book-shaped hinged test device. A throat swab is inserted into the swab well, extraction reagents are added from dropper bottles, the swab is rotated three times, and following a 1 minute incubation, the test device is closed. Extracted antigen captured by immobilized anti-Strep A antibody reacts to bind the visualizing gold-conjugate. There are no transferring steps, the sample is contained, and results are available within 6 minutes.
Here's a breakdown of the acceptance criteria and study information for the Binax Strep A Test, based on the provided text:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance (Binax Strep A Test) |
|---|---|
| Sensitivity | 80% (compared to culture) |
| Specificity | 97% (compared to culture) |
Note: The document compares the Binax test's performance to two predicate devices: QuickVue In-Line One-Step and Abbott TestPack Plus. For sensitivity, the predicate devices had 90%. For specificity, QuickVue had 96% and Abbott had 95%.
Study Details
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Sample sizes used for the test set and the data provenance:
- Clinical Efficacy (Sensitivity & Specificity): 81 physician office patients. The data provenance is from physician offices, implying clinical utility. It is a retrospective study since the swabs were collected and then tested.
- Specificity with Sore Throat Medication: 20 culture-negative samples from subjects who had consumed sore throat medication. This was to further demonstrate specificity.
- Reproducibility: 60 blind-coded sample swabs per operator (for 6 operators).
- Cross-reactivity: 25 different organisms tested (number of samples per organism not specified).
- Control Evaluation: 20 kit controls run in a panel of 20 devices (8 rendered inoperative) for each of 3 operators.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience):
The document does not explicitly state the number or qualifications of experts used to establish the ground truth. It refers to "culture" as the "Gold Standard" but doesn't detail who performed or interpreted these cultures. -
Adjudication method (e.g., 2+1, 3+1, none) for the test set:
The document does not specify any adjudication method used for the test set data. -
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:
This is an in vitro diagnostic (IVD) device, not an AI-assisted diagnostic tool. Therefore, an MRMC comparative effectiveness study involving human readers with and without AI assistance is not applicable and was not performed. -
If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
This is a standalone diagnostic test (Binax Strep A Test) that provides a direct result. Its performance is evaluated independently, without a human interpretation loop in the way an AI algorithm might be assessed. So, yes, a standalone performance assessment was done. -
The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
The primary ground truth used for sensitivity and specificity determination was culture (specifically, "sheep blood agar confirmed positive specimens"). This is referred to as the "Gold Standard." -
The sample size for the training set:
The document does not mention a separate "training set" in the context of machine learning or algorithm development. The reported studies evaluate the performance of the device itself. -
How the ground truth for the training set was established:
Since no explicit "training set" for an algorithm is mentioned, this question is not applicable. The device's performance was evaluated against the "Gold Standard" of culture.
§ 866.3740
Streptococcus spp. serological reagents.(a)
Identification. Streptococcus spp. serological reagents are devices that consist of antigens and antisera (excluding streptococcal exoenzyme reagents made from enzymes secreted by streptococci) used in serological tests to identifyStreptococcus spp. from cultured isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by bacteria belonging to the genusStreptococcus and provides epidemiological information on these diseases. Pathogenic streptococci are associated with infections, such as sore throat, impetigo (an infection characterized by small pustules on the skin), urinary tract infections, rheumatic fever, and kidney disease.(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.