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The Clearview Advanced™ Strep A test is a rapid chromatographic immunoassay for the qualitative detection of Strep A antigen from throat swab specimens as an aid in the diagnosis of Group A Streptococcal infection.

The Clearview Advanced™ Strep A test is a qualitative, lateral flow immunoassay for the detection of Strep A carbohydrate antigen directly from a throat swab sample. To perform the test, Reagent 1 (R1) is added to the extraction tube which is coated with a mixture of conjugate antibodies and a lytic enzyme extraction reagent. The lytic enzyme is mixed with colloidal gold conjugated to rabbit anti-Strep A and a second colloidal gold control coniugate antibody. The reagents are dried onto the bottom of an extraction tube forming a red spot. The extraction/conjugate pellet is resuspended with R1 and the throat swab is added to the extraction tube. The Strep A antigen is extracted from the sample and the swab is removed. The test strip is immediately placed in the extracted sample. If Group A Streptococcus is present in the sample, it will react with the anti-Strep A antibody conjugated to the gold particle. The complex will then be bound by the anti-Strep A capture antibody and a visible red test line will appear, indicating a positive result. To serve as an onboard procedural control, the blue line observed at the control site prior to running the assay will turn red, indicating that the test has been performed properly. If Strep A antigen is not present, or present at very low levels, only a red control line will appear. If the red control line does not appear, or remains blue, the test result is invalid.

Here's a breakdown of the acceptance criteria and study details for the Clearview Advanced™ Strep A Test, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

• Diluent (True Negative): 0% (0/179)
• 1x10^5 (Moderate Positive): 99% (179/180)
• 1x10^4 (LOD/C95 Concentration): 94% (170/180)
• 3.2x10^3 (Near the cut-off/C50 Concentration): 49% (88/179) |

Note on Acceptance Criteria: The document does not explicitly state numerical acceptance criteria for sensitivity and specificity. However, regulatory bodies implicitly expect high performance from diagnostic tests for infectious diseases. The provided confidence intervals indicate a robust performance profile. For analytical sensitivity and specificity, the acceptance criteria are described directly in the text (e.g., "produces positive... approximately 95% of the time" for LOD, and "all... were negative" for cross-reactivity).

2. Sample Size Used for the Test Set and Data Provenance

• Sample Size (Clinical Performance Test Set): A total of 297 throat swab specimens.
• Data Provenance:
  • Country of Origin: United States.
  • Retrospective or Prospective: Prospective clinical study.
  • Study Design: Multi-center study conducted in 2008-2009 at five geographically diverse physician offices, clinics, and emergency departments.

3. 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 used to establish the ground truth or their qualifications. The ground truth ("bacterial culture") is an objective laboratory method rather than an expert interpretation in this context.

4. Adjudication Method for the Test Set

• The document does not describe an adjudication method. The comparison is directly between the Clearview Advanced Strep A test results and the bacterial culture results.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

• No, an MRMC comparative effectiveness study was not done. This study assesses the performance of a device (immunoassay) against a gold standard (bacterial culture), not how human readers improve with or without AI assistance.

6. Standalone Performance Study

• Yes, a standalone performance study was done. The entire clinical performance section describes the algorithm's (device's) performance without human intervention in interpreting the test result. The test is a qualitative, lateral flow immunoassay where the visual appearance of a line directly indicates a positive or negative result, and its accuracy is compared to the bacterial culture.

7. Type of Ground Truth Used

• Bacterial Culture. The clinical performance of the Clearview Advanced Strep A test was established by comparing its results to bacterial culture, which is considered the gold standard for diagnosing Group A Streptococcal infection.

8. Sample Size for the Training Set

• The document does not specify a separate training set or its sample size. The description of the clinical study refers to the "test set" or "evaluation set" for performance metrics. For traditional immunoassay devices like this, there isn't typically a distinct "training set" in the machine learning sense. The device's design and parameters are developed through analytical studies (e.g., LOD, cross-reactivity) rather than through training on a large dataset of patient samples.

9. How the Ground Truth for the Training Set Was Established

• Since there's no explicitly defined "training set" in the context of machine learning for this device, a ground truth establishment method for it is not applicable/not described. The robust design of the immunoassay, informed by analytical studies, serves as its "training" or development process.

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