(312 days)
Abbott TestPack Plus Strep A with On Board Controls (OBC) II is a rapid immunoassay for the qualitative detection of Group A Streptococcal (Group A Strep) antigen in throat swab specimens from patients with suspected Group A Strep associated pharyngitis and for confirmation of presumptive Group A Strep colonies isolated on culture plates.
TestPack Plus Strep A with OBC II is a rapid immunoassay for the qualitative detection of Group A Streptococcal antigen from throat swab specimens or confirmation of presumptive Group A Strep colonies recovered from culture. TestPack Plus Strep A with OBC II utilizes an internal on board control system consisting of six control features.
Here's a breakdown of the acceptance criteria and the study details for the Abbott TestPack® Plus™ Strep A with OBC® II, based on the provided text:
Acceptance Criteria and Device Performance
The provided text doesn't explicitly state pre-defined acceptance criteria (e.g., "The device must achieve sensitivity of at least X%"). Instead, it compares the device's performance to that of the predicate methods (SBA culture and SSA culture) to demonstrate substantial equivalence. The reported performance of the device serves as the basis for this comparison.
Table of Acceptance Criteria (Implied by Predicate Performance) and Reported Device Performance:
| Performance Metric | Implied Acceptance Criteria (via Predicate: SBA Culture) | Reported Device Performance (TestPack Plus Strep A with OBC® II vs. SBA Culture) | Implied Acceptance Criteria (via Predicate: SSA Culture) | Reported Device Performance (TestPack Plus Strep A with OBC® II vs. SSA Culture) |
|---|---|---|---|---|
| Sensitivity | (Performance similar to SBA culture) | 92.9% at End of Assay (EOA), 94.6% at 10 minutes | (Performance similar to SSA culture) | 90.4% at EOA, 92.2% at 10 minutes |
| Specificity | (Performance similar to SBA culture) | 97.9% at EOA, 97.0% at 10 minutes | (Performance similar to SSA culture) | 97.9% at EOA, 97.0% at 10 minutes |
| Agreement | (Performance similar to SBA culture) | 96.6% at EOA, 96.4% at 10 minutes | (Performance similar to SSA culture) | 96.0% at EOA, 95.7% at 10 minutes |
Note: The acceptance criteria are "implied" because the document focuses on demonstrating substantial equivalence rather than meeting pre-defined quantitative thresholds. The goal was to show that the new device performs comparably to established methods.
Study Details:
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Sample Size Used for the Test Set and Data Provenance:
- Sample Size: 445 throat swabs.
- Data Provenance:
- Country of Origin: U.S. (collected at five U.S. clinical sites).
- Retrospective or Prospective: Prospective. The swabs were collected from "patients seeking medical attention for pharyngitis," and then used to inoculate culture plates within 30 minutes. This indicates a forward-looking collection as part of the study.
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Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
- The document does not specify the number of experts or their qualifications for establishing the ground truth. It states that "Suspect beta-hemolytic colonies were confirmed as Group A Strep by a latex agglutination test." This implies a standard laboratory procedure performed by trained personnel, but specific numbers or credentials are not provided.
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Adjudication Method for the Test Set:
- The document does not describe a specific adjudication method like 2+1 or 3+1. The ground truth was established by laboratory confirmation (latex agglutination test) of suspect colonies from the culture plates, which is a standard diagnostic procedure rather than an expert consensus/adjudication process in the typical sense for imaging or clinical decision scenarios.
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If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done:
- No, an MRMC comparative effectiveness study was not done. This study is for an in-vitro diagnostic (IVD) device that detects a specific antigen, not an imaging or an AI-assisted diagnostic tool that would involve multiple human readers interpreting results with and without AI.
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If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:
- Yes, this was a standalone performance study. The TestPack Plus Strep A with OBC II assay itself provides the result, which is then compared to the culture results. There is no "human-in-the-loop" aspect to the device's performance that is being evaluated in this context. The device directly detects the antigen.
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The Type of Ground Truth Used:
- Culture confirmation/Pathology: The primary ground truth was established by isolating Group A Strep colonies on 5% Sheep Blood Agar (SBA) and Strep Selective Sheep Blood Agar (SSA) culture plates, followed by confirmation using a latex agglutination test. This is a microbiological gold standard for identifying Group A Streptococcus.
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The Sample Size for the Training Set:
- The document does not mention a training set. This is because the TestPack Plus Strep A with OBC II is a rapid immunoassay (a rapid diagnostic test), not an AI/machine learning model that requires a training set. The device operates based on a pre-defined chemical/biological reaction, not learnable parameters.
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How the Ground Truth for the Training Set Was Established:
- Not applicable, as there was no training set for this type of device.
§ 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.