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The Lyra™ Parainfluenza Virus Assay is a Real-Time PCR assay for the qualitative detection and identification of human parainfluenza virus types 1, 2 and 3 viral RNA from nasal and nasopharyngeal swab specimens from symptomatic patients. It is intended for use as an aid in the differential diagnosis of parainfluenza virus types 1, 2 and 3. This test is not intended to detect Parainfluenza 4a or Parainfluenza 4b viruses.

Negative results do not preclude parainfluenza virus infection and should not be used as the sole basis for treatment or other patient management decisions.

The Lyra™ Parainfluenza Virus Assay is a Real-Time PCR assay for the qualitative detection and identification of human parainfluenza virus types 1, 2 and 3 viral RNA from nasal and nasopharyngeal swab specimens from symptomatic patients. The assay detects viral nucleic acids that have been extracted from a patient sample. A multiplex Real-time RT-PCR reaction is carried out under optimized conditions in a single tube generating amplicons for PIV-1, PIV-2, PIV-3 and the Process Control (PRC). Identification of PIV-1, PIV-2, PIV-3 and the PRC occurs by the use of target-specific primers and fluorescent-labeled probes that hybridize to conserved regions in the genomes of PIV-1. PIV-2. PIV-3 and the PRC.

Here's a summary of the acceptance criteria and study details for the Lyra™ Parainfluenza Virus Assay, based on the provided document:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state pre-defined acceptance criteria in terms of numerical thresholds for sensitivity or specificity. However, based on the conclusions regarding "good sensitivity and specificity" and "good positive and negative percent agreement," we can infer the expected performance. The reported performance is presented below:

2. Sample Size for Test Set and Data Provenance

• Prospective Study:
  • Sample Size: 1241 fresh upper respiratory tract specimens.
  • Data Provenance: Not explicitly stated, but the "Prospective multi-center study" suggests samples were collected from various clinical sites. The specimens were sent to a "central location" for comparative testing, implying multi-site collection.
  • Retrospective Study:
  • Sample Size: 105 frozen upper respiratory tract specimens.
  • Data Provenance: Specimens "obtained from a pediatric hospital in the Southwest United States."

3. Number of Experts and Qualifications for Ground Truth

• Prospective Study: The ground truth was established using "direct specimen fluorescent antibody (DSFA) and cell culture with DFA (CCFA)." The document does not specify the number or qualifications of experts involved in performing or interpreting these reference methods.
• Retrospective Study: The ground truth was established using a legally marketed predicate device, the "Prodesse ProParaFlu+ assay (K091053)." The document does not mention experts establishing this ground truth, as it's a comparison against another device.

4. Adjudication Method for the Test Set

The document does not describe a formal adjudication method (e.g., 2+1, 3+1) for the test sets. For discrepant results in the prospective study, an "additional RT-PCR assay" was used for a subset of samples (e.g., 2 of 3 PIV-1 false positives, all 5 PIV-3 false positives). Similarly, for the retrospective study, an "additional RT-PCR assay" was used for 1 PIV-1 false positive and all 5 PIV-2 false positives. This implies a reference method approach, potentially with further molecular confirmation for outliers.

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

No multi-reader multi-case (MRMC) comparative effectiveness study was done. The document describes a standalone performance study of the device against reference methods and another legally marketed device; it does not involve human readers or assess improvement with AI assistance.

6. Standalone (Algorithm Only) Performance Study

Yes, a standalone performance study was done. The Lyra™ Parainfluenza Virus Assay, a Real-Time PCR assay (an algorithm-based diagnostic test, not requiring human interpretation of output beyond reading the results), was evaluated on its own against established reference methods (DSFA and CCFA in the prospective study, and the Prodesse ProParaFlu+ assay in the retrospective study).

7. Type of Ground Truth Used

• Prospective Study: Expert consensus, specifically a composite reference method of direct specimen fluorescent antibody (DSFA) and cell culture with DFA (CCFA).
• Retrospective Study: A legally marketed predicate device (Prodesse ProParaFlu+ assay).

8. Sample Size for the Training Set

The document does not provide information on the sample size for a training set. This is a diagnostic assay, and the studies described are performance evaluations, not specifically machine learning model training. The assay's design would have involved internal development and analytical verification, but the term "training set" as commonly used for machine learning is not applicable or detailed here.

9. How Ground Truth for the Training Set Was Established

As no specific "training set" is described in the context of machine learning, this information is not provided. The development of the assay would have been based on established molecular biology principles and analytical validation using known positive and negative controls/samples.

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