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The BD MAX™ Enteric Viral Panel performed on the BD MAX System, is an automated in vitro diagnostic test for the direct qualitative detection and differentiation of enteric viral pathogens. The BD MAX™ Enteric Viral Panel detects nucleic acids from

• Norovirus GI & GII
• . Rotavirus A
• . Adenovirus F40/41
• Sapovirus (genogroups I, II, IV, V)
• . Human Astrovirus (hAstro)

Testing is performed on unpreserved soft to diarrheal or Cary-Blair preserved stool specimens from symptomatic patients with suspected acute gastroenteritis or colitis. The test is performed directly on the specimen, utilizing real-time polymerase chain reaction (PCR) for the amplification of relevant gene target DNA/RNA. The test utilizes fluorogenic gene-specific hybridization probes for the detection of the amplified DNA.

This test is intended for use, in conjunction with clinical presentation, laboratory findings, and epidemiological information, as an aid in the differential diagnosis of Norovirus GI & GII, Rotavirus A, Adenovirus F40/41, Sapovirus (genogroups I, II, IV, V), and Astrovirus infections. Results of this test should not be used as for diagnosis, treatment, or other patient management decisions. Positive results do not rule out co-infection with other organisms that are not detected by this test, and may not be the sole of patient illness. Negative results in the setting of clinical illness compatible with gastroenteritis may be due to infection by pathogens that are not detected by this test or non-infectious causes such as ulcerative colitis, irritable bowel syndrome, or Crohn's disease.

The BD MAX™ Enteric Viral Panel assay along with the BD MAX™ System are comprised of an instrument with associated hardware and accessories, disposable microfluidic cartridges, master mixes, unitized reagent strips, and extraction reagents. The instrument automates sample preparation including target lysis, nucleic acid extraction and concentration, reagent rehydration, target nucleic acid amplification and detection using real-time PCR. The assay includes a Sample Processing Control (SPC) that is present in the Extraction Tube. The SPC monitors nucleic acid extraction steps, thermal cycling steps, reagent integrity and the presence of inhibitory substances. The BD MAX™ System software automatically interprets test results. For the BD MAX™ Enteric Viral Panel, a test result may be called as POS, NEG, or UNR (Unresolved) based on the amplification status of the targets and of the Sample Processing Control. IND (Indeterminate) or INC (Incomplete) results are due to BD MAX™ System failure.

The document describes the performance evaluation of the BD MAX™ Enteric Viral Panel with the Copan FecalSwab Collection, Preservation, and Transport System compared to the previously cleared Cary-Blair preserved stool specimens. The studies were conducted to demonstrate substantial equivalence for the additional specimen collection method.

Here's a breakdown of the requested information:

1. Table of Acceptance Criteria and Reported Device Performance

The document provides specific acceptance criteria for the "User Variability Study" and performance results for the "Multicenter Clinical Study" where the BD MAX™ Enteric Viral Panel (EVP) was compared using FecalSwab™ to Cary-Blair preserved samples.

User Variability Study Acceptance Criteria and Performance:

Multicenter Clinical Study Reported Device Performance (PPA = Positive Percent Agreement, NPA = Negative Percent Agreement) for FecalSwab™ compared to Cary-Blair results as reference:

Limit of Detection (LoD) Study Acceptance Criteria and Performance:
Acceptable performance was demonstrated when the detection break points between the FecalSwab and Cary-Blair Para-Pak® specimen types were within one five-fold dilution of each other. Breakpoint is defined as the highest concentration where the positivity rate is < 95% (< 23/24).
The study concluded that "All FecalSwabTM break points were within one five-fold concentration when compared to Para-Pak®."

2. Sample size used for the test set and the data provenance

• Limit of Detection (LoD) Study:

  • Test Set Sample Size: For each of the 5 assay targets, a five-fold serial dilution (titration) was performed, resulting in 5 dilutions. Each dilution was tested in 24 replicates for both Cary-Blair and FecalSwab sample types. This means 5 (dilutions) * 24 (replicates/dilution) * 2 (sample types) = 240 tests per organism. With 5 organisms tested, it's 240 * 5 = 1200 individual tests (excluding QC and controls).
  • Data Provenance: The study was conducted by the manufacturer, likely in a laboratory setting, to compare analytical sensitivity. The specific country of origin is not explicitly stated but implies internal study based in the US. It's a prospective, controlled laboratory study.

• User Variability Study:

  • Test Set Sample Size: Six different users prepared 2 FecalSwab™ specimens for each of 5 panel members (1 negative, 3 low-positive, 1 moderate-positive). This results in 6 (users) * 2 (specimens/user/panel member) * 5 (panel members) = 60 FecalSwab™ specimens prepared. Each specimen was then tested. Specifically, there were 12 negative samples, 36 low-positive samples, and 12 moderate-positive samples.
  • Data Provenance: This was an internal, prospective laboratory study conducted by the manufacturer. Specific country of origin not stated.

• Multicenter Clinical Study:

  • Total Enrolled Specimens: 802 compliant specimens (591 prospective and 211 retrospective).
  • Final Data Analysis Set: 581 compliant prospective and 211 compliant retrospective subjects.
  • Data Provenance:
    • Country of Origin: Not explicitly stated, but derived from "eight (8) geographically diverse clinical centers" for the prospective samples, suggesting a multi-center study, potentially within the US.
    • Retrospective/Prospective: Both. 591 prospective specimens were collected as part of routine patient care from symptomatic patients. 211 retrospective specimens were included.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

The document does not mention the use of experts to establish ground truth for any of the studies. All studies appear to rely on laboratory-determined results (e.g., from the Cary-Blair predicate device or expected results for contrived samples) as the reference standard.

4. Adjudication method for the test set

The document does not discuss an adjudication method. The clinical study compares the FecalSwab™ results against the Cary-Blair preserved samples as the reference standard. For the LoD and User Variability studies, the results are compared against expected outcomes or the predicate device's performance.

5. 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

No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. The device is an automated in vitro diagnostic test (IVD) for direct pathogen detection, not an AI-assisted diagnostic imaging or analysis tool that would involve human readers.

6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done

Yes, the studies performed were standalone performance evaluations of the BD MAX™ Enteric Viral Panel with the FecalSwab™ System. The device is an automated IVD platform. The evaluation focuses on the analytical and clinical performance of the device itself (including sample collection and processing methods), not on human-in-the-loop performance or AI assistance.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

• Limit of Detection Study: The ground truth was established by preparing known concentrations of quantified viral stocks or positive stools.
• User Variability Study: Ground truth was established by creating negative, low-positive, and moderate-positive panel members with known reactivity.
• Multicenter Clinical Study: The ground truth for clinical specimens was the results obtained from testing the same unpreserved stool samples preserved in Cary-Blair (the predicate method). For Adenovirus, contrived positive and negative specimens with known results were also used to supplement limited positive clinical samples.

8. The sample size for the training set

The document does not specify a separate "training set" in the context of machine learning or AI. These are performance evaluation studies for an IVD diagnostic test. The existing BD MAX™ Enteric Viral Panel was already cleared (K181427), and these studies are for validating the use of a new sample collection method (FecalSwab) with the existing panel. The development and internal validation of the initial BD MAX™ EVP assay would have involved extensive sample testing, but details of that "training" are not in this document.

9. How the ground truth for the training set was established

As there is no explicitly mentioned "training set" in the context of an AI/ML device in this document, this question is not directly applicable. If referring to the development of the initial BD MAX™ Enteric Viral Panel, the ground truth would have been established through a combination of well-characterized clinical specimens and analytically prepared samples with known viral presence/absence, likely confirmed by reference methods (e.g., PCR, sequencing, culture where applicable).

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