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The BD Veritor™ System for Rapid Detection of Flu A+B CLIA-Waived Kit is a rapid chromatographic immunoassay for the direct and qualitative detection of influenza A and B viral nucleoprotein antigens from nasal and nasopharyngeal swabs of symptomatic patients. The BD Veritor™ System for Rapid Detection of Flu A+B CLIA-Waived Kit (also referred to as the BD Veritor System and BD Veritor System Flu A+B) is a differentiated test, such that influenza A viral antigens can be distinguished from influenza B viral antigens from a single processed sample using a single device. The test is to be used as an aid in the diagnosis of influenza A and B viral infections. A negative test is presumptive, and it is recommended that these results be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions. The test is not intended to detect influenza C antigens.

Performance characteristics for influenza A and B were established during January through March of 2011 when influenza viruses A/2009 H1N1, A/H3N2, B/Victoria lineage, and B/Yamagata lineage were the predominant influenza viruses in circulation according to the Morbidity and Mortality Weekly Report from the CDC entitled "Update: Influenza Activity-United States, 2010-2011 Season, and Composition of the 2011-2012 Influenza Vaccine." Performance characteristics may vary against other emerging influenza viruses.

If infection with a novel influenza virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to the state or local health department for testing. Virus culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.

The BD Veritor™ System for Rapid Detection of Flu A+B CLIA Waived Kit is a rapid chromatographic immunoassay for the direct and qualitative detection of influenza A and B viral antigens from nasopharyngeal and nasal swabs of symptomatic patients. The test is to be used as an aid in the diagnosis of influenza A and B viral infections. It is a differentiated test, such that influenza A viral antigens can be distinguished from influenza B viral antigens from a single processed sample using a single test device. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other management decisions. All negative test results should be confirmed by another methodology, such as a nucleic acid-based method.

BD Veritor™ System Flu A+B test devices are interpreted by a BD Veritor™ Plus Analyzer. When using the BD Veritor™ Plus Analyzer, workflow steps depend on the selected operational mode and the Analyzer configuration settings. In Analyze Now mode, the instrument evaluates assay devices after manual timing of their development. In Walk Away mode, devices are inserted immediately after application of the specimen, and timing of assay development and analysis is automated.

The BD Veritor™ System Flu A+B CLIA-Waived Kit is an immuno-chromatographic assay for detection of influenza A and B viral antigens in samples processed from respiratory specimens. The viral antigens detected by the BD Flu A+B test are nucleoprotein, not hemagglutinin (HA) or neuraminidase (NA) proteins. Flu viruses are prone to minor point mutations (i.e., antigenic drift) in either one or both of the surface proteins (i.e., HA or NA). The BD Flu A+B test is not affected by antigenic drift or shift because it detects the highly conserved nucleoprotein of the influenza viruses. To perform the test, the patient specimen swab is treated in a supplied reaction tube prefilled with a lysing agent that serves to expose the target viral antigens, and then expressed through a filter tip into the sample well on a BD Veritor"10 Flu A+B test device. Any influenza A or influenza B viral antigens present in the specimen bind to anti-influenza antibodies conjugated to colloidal gold micro-particles on the BD Veritor™ Flu A+B test strip. The antigen-conjugate complex then migrates across the test strip to the capture zone and reacts with either Anti-Flu A or Anti-Flu B antibodies that are immobilized on the two test lines on the membrane.

The BD Flu A+B test device shown in Figure 1 is designed with five spatially distinct zones including positive and negative control line positions, separate test line positions for the target analytes, and a background zone. The test lines for the target analytes are labeled on the test device as 'A' for flu A position, and 'B' for flu B position. The onboard positive control ensures the sample has flowed correctly and is indicated on the test device as 'C'. Two of the five distinct zones on the test device are not labeled. These two zones are an onboard negative control line and an assay background zone. The active negative control feature in each test identifies and compensates for specimen-related, nonspecific signal generation. The remaining zone is used to measure the assay background.

The BD Veritor™ Plus Analyzer is a digital immunoassay instrument that uses a reflectance-based measurement method and applies assay specific algorithms to determine the presence or absence of the target analyte. The Analyzer supports the use of different assays by reading an assay-specific barcode on the test device. Depending on the configuration chosen by the operator, the instrument communicates status and results to the operator via a liquid crystal display (LCD) on the instrument, a connected printer, or through a secure connection to the facility's information system.

In the case of the Flu A + B test, the BD Veritor™ Plus Analyzer subtracts nonspecific signal at the negative control line from the signal present at both the Flu A and Flu B test lines. If the resultant line signal is above a pre-selected assay cutoff, the specimen scores as positive. If the resultant line signal is below the cutoff, the specimen scores as negative. Use of the active negative control feature allows the BD Veritor™ Plus Analyzer to correctly interpret test results that cannot be scored visually because the human eye is unable to accurately perform the subtraction of the nonspecific signal. The measurement of the assay background zone is an important factor during test interpretation as the reflectance is compared to that of the control and test zones. A background area that is white to light pink indicates the device has performed correctly.

The provided text describes a 510(k) premarket notification for modifications to the BD Veritor™ System for Rapid Detection of Flu A+B CLIA-Waived Kit. The current submission (K232434) focuses on changes to the BD Veritor™ Plus Analyzer, not the assay itself. Therefore, the details about acceptance criteria and clinical performance studies relate to the predicate device (K223016) and the assay's original clearance (K180438), as the modifications in K232434 do not impact the assay's analytical or clinical performance.

Here's a breakdown based on the provided input:

1. Table of Acceptance Criteria and Reported Device Performance

The current submission (K232434) is for modifications to the analyzer, not a new or modified assay. Therefore, it does not present new acceptance criteria or device performance data for the assay's diagnostic accuracy. Instead, it relies on the previously established performance of the predicate device (K223016) which itself relies on the performance established in K180438. The acceptance criteria for the current submission are related to the safety and electromagnetic compatibility of the modified analyzer.

Performance Characteristics for Influenza A and B (as established for K180438 / K223016 and referenced here):

The document mentions that performance characteristics for influenza A and B were established during January through March of 2011. While specific sensitivity and specificity values are not provided in this document excerpt, the "Indications for Use" and "Intended Use" sections clearly state that the device is for "direct and qualitative detection of influenza A and B viral nucleoprotein antigens."

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

The provided text does not include the specific sample size for the test set used to establish the clinical performance of the Flu A+B assay, nor does it explicitly state the data provenance (e.g., retrospective or prospective studies) in detail, beyond mentioning:

• "Performance characteristics for influenza A and B were established during January through March of 2011"
• This period corresponded to when "influenza viruses A/2009 H1N1, A/H3N2, B/Victoria lineage, and B/Yamagata lineage were the predominant influenza viruses in circulation" in the United States, according to CDC reports. This implies real-world, clinical data from symptomatic patients in the US during that influenza season was used.

Since the current submission is for analyzer modifications and explicitly states, "Clinical Performance: Clinical performance testing was not required because the changes made to the Analyzer do not have an impact on the assay-specific clinical performance," this information would be found in the original submission (K180438) that cleared the assay.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of those Experts

This information is not provided in the given text. It would be part of the detailed clinical study report from the original assay clearance (K180438).

4. Adjudication Method for the Test Set

This information is not provided in the given text. It would be part of the detailed clinical study report from the original assay clearance (K180438).

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

This is not applicable to the BD Veritor System. This device is a rapid chromatographic immunoassay read by a digital analyzer (BD Veritor™ Plus Analyzer), not an AI system designed to assist human readers in interpreting complex images or data. The analyzer automatically interprets the test results based on its algorithms and provides a positive, negative, or invalid result, rather than providing input to a human reader for their interpretation.

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

Yes, in essence, the BD Veritor™ Plus Analyzer operates as a standalone algorithm without human-in-the-loop performance for result interpretation. The text states:

• "The Analyzer is a digital immunoassay instrument that uses a reflectance-based measurement method and applies assay specific algorithms to determine the presence or absence of the target analyte."
• "The BD Veritor™ Plus Analyzer subtracts nonspecific signal at the negative control line from the signal present at both the Flu A and Flu B test lines. If the resultant line signal is above a pre-selected assay cutoff, the specimen scores as positive. If the resultant line signal is below the cutoff, the specimen scores as negative."
• "Use of the active negative control feature allows the BD Veritor™ Plus Analyzer to correctly interpret test results that cannot be scored visually because the human eye is unable to accurately perform the subtraction of the nonspecific signal."

This clearly describes an automated interpretation process by the device's algorithms.

7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)

The document states, "A negative test is presumptive, and it is recommended that these results be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay." This implies that viral culture or an FDA-cleared influenza A and B molecular assay served as the reference standard (ground truth) for establishing performance characteristics during the original clinical studies.

8. The Sample Size for the Training Set

This information is not provided in the given text, and it's less relevant for an immunoassay where "training data" for a machine learning model might not be explicitly defined in the same way as for complex AI algorithms. For immunoassays, the "training" involves optimizing the assay reagents and conditions, and setting cutoff values, which are then validated with clinical samples.

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

This information is not provided in the given text. As mentioned above, the concept of a "training set ground truth" might not apply directly in the traditional sense for this type of immunoassay. Instead, the ground truth for establishing performance (and implicitly for setting cutoffs) would be established using the reference methods mentioned in point 7.

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The BD Veritor System for Rapid Detection of Flu A+B is a rapid chromatographic immunoassay for the direct and qualitative detection of influenza A and B viral nucleoprotein antigens from nasal and nasopharyngeal swabs of symptomatic patients. The BD Veritor System for Rapid Detection of Flu A+B (also referred to as the BD Veritor System and BD Veritor System Flu A+B) is a differentiated test, such that influenza A viral antigens can be distinguished from influenza B viral antigens from a single processed sample using a single device. The test is to be used as an aid in the diagnosis of influenza A and B viral infections. A negative test is presumptive and it is recommended that these results be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Outside the U.S., a negative test is presumptive and it is recommended that these results be confirmed by viral culture or a molecular assay cleared for diagnostic use in the country of use. FDA has not cleared this device for use outside of the U.S. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions. The test is not intended to detect influenza C antigens.

The BD Veritor System for Rapid Detection of Flu A+B is a rapid chromatographic immunoassay for the direct and qualitative detection of influenza A and B viral antigens from nasopharyngeal and nasal swabs of symptomatic patients. The test is to be used as an aid in the diagnosis of influenza A and B viral infections. It is a differentiated test, such that influenza A viral antigens can be distinguished from influenza B viral antigens from a single processed sample using a single test device. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other management decisions. All negative test results should be confirmed by another methodology, such as a nucleic acid based method. All BD Veritor System Flu A+B test devices are interpreted by a BD Veritor System Instrument, either a BD Veritor Reader or BD Veritor Plus Analyzer.

The BD Veritor Flu A+B test is an immuno-chromatographic assay for detection of influenza A and B viral antigens in samples processed from respiratory specimens. The viral antigens detected by the BD Flu A+B test are nucleoprotein, not hemagglutinin (HA) or neuraminidase (NA) proteins. Flu viruses are prone to minor point mutations (i.e., antigenic drift) in either one or both of the surface proteins (i.e., HA or NA). The BD Flu A+B test is not affected by antigenic drift or shift because it detects the highly conserved nucleoprotein of the influenza viruses 12. To perform the test, the patient specimen swab is treated in a supplied reaction tube prefilled with a lysing agent that serves to expose the target viral antigens, and then expressed through a filter tip into the sample well on a BD Veritor Flu A+B test device. Any influenza A or influenza B viral antigens present in the specimen bind to anti-influenza antibodies conjugated to colloidal gold micro-particles on the Veritor Flu A+B test strip. The antigen-coniugate complex then migrates across the test strip to the capture zone and reacts with either Anti-Flu A or Anti-Flu B antibodies that are immobilized on the two test lines on the membrane.

The BD Flu A+B test device shown in Figure 1 is designed with five spatially-distinct zones including positive and negative control line positions, separate test line positions for the target analytes, and a background zone. The test lines for the target analytes are labeled on the test device as 'A' for flu A position, and 'B' for flu B position. The onboard positive control ensures the sample has flowed correctly and is indicated on the test device as 'C'. Two of the five distinct zones on the test device are not labeled. These two zones are an onboard negative control line and an assay background zone. The active negative control feature in each test identifies and compensates for specimen-related, nonspecific signal generation. The remaining zone is used to measure the assay background.

The Veritor System is made up of assay kits with analyte specific reagents and an optoelectronic interpretation instrument.

The BD Veritor System instruments use a reflectance-based measurement method and apply assay specific algorithms to determine the presence or absence of the target analyte. In the case of the Flu A + B test. the BD Veritor System instruments subtract nonspecific signal at the negative control line from the signal present at both the Flu A and Flu B test lines. If the resultant line signal is above a pre-selected assay cutoff, the specimen scores as positive. If the resultant line signal is below the cutoff, the specimen scores as negative. Use of the active negative control feature allows the BD Veritor System instruments to correctly interpret test results that cannot be scored visually because the human eye is unable to accurately perform the subtraction of the nonspecific signal. The measurement of the assay background zone is an important factor during test interpretation as the reflectance is compared to that of the control and test zones. A background area that is white to light pink indicates the device has performed correctly. Sample preparation is the same for use with both instruments, and both can utilize the same kit components. Neither instrument requires calibration.

The Veritor Reader and the Veritor Plus Analyzer use the functional components and decision algorithm in the firmware. The BD Veritor Plus Analyzer has the flexibility of an optional bar code scanning module and cellular connectivity designed to facilitate record keeping as well as the addition of a "Walk Away" work flow mode. Depending on the configuration chosen by the operator, the Veritor Plus Analyzer communicates status and results to the operator via a liquid crystal display (LCD) on the instrument, a connected printer, or through a secure connection to the facility's information system.

Here's a breakdown of the acceptance criteria and study information for the BD Veritor System for Rapid Detection of Flu A + B CLIA Waived Kit, based on the provided document:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state "acceptance criteria" numerical targets. Instead, it presents performance data compared to a reference method (PCR) which implies these are the achieved performance metrics considered acceptable for substantial equivalence. The key performance indicators are Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA) for influenza A and B.

2. Sample Size and Data Provenance for the Test Set

The reported performance data in the table (PPA and NPA) are derived from a test set with the following characteristics:

• Sample Size for Influenza A: 736 total samples (226 PCR positive, 510 PCR negative).
• Sample Size for Influenza B: 736 total samples (171 PCR positive, 565 PCR negative).
• Data Provenance: The document states the performance characteristics were established "during January through March of 2011" and summarizes data "across all age groups, clinical testing sites and sample types." This indicates a prospective clinical study involving collection of symptomatic patient samples. The country of origin is not explicitly stated for the "All Sites" data, but given it's an FDA submission, it's highly likely to include data from the United States. It is a prospective study during the influenza season.

3. Number of Experts and Qualifications for Ground Truth

The document does not mention the use of human experts to establish ground truth for the primary clinical performance data. The reference method for ground truth was a Molecular Assay (PCR).

4. Adjudication Method for the Test Set

Not applicable, as the ground truth was established by a molecular assay (PCR), not expert consensus.

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

The document does not describe an MRMC comparative effectiveness study involving human readers with and without AI assistance. The device is a rapid chromatographic immunoassay interpreted by an instrument (BD Veritor Reader or Veritor Plus Analyzer), not an AI-assisted diagnostic for human readers.

The device itself is an automated system for interpreting rapid tests, not a tool to assist human readers in interpreting complex images or data.

6. Standalone (Algorithm Only) Performance

Yes, the study focuses on the standalone performance of the BD Veritor System (the rapid immunoassay device interpreted by the Veritor Reader or Veritor Plus Analyzer). The reported PPA and NPA values represent the performance of the device itself against a reference standard (PCR) without human interpretation.

The "Principle of the Test" section explains: "All BD Veritor System Flu A+B test devices are interpreted by a BD Veritor System Instrument, either a BD Veritor Reader or BD Veritor Plus Analyzer." The instrument's algorithms make the determination.

7. Type of Ground Truth Used

The ground truth used for the clinical performance evaluation was PCR (Polymerase Chain Reaction), which is a molecular assay for detecting influenza A and B. It is referred to as "Reference PCR" in the performance tables.

8. Sample Size for the Training Set

The document does not provide specific details on the sample size used for the training set of the device's inherent algorithms or cutoff thresholds. It mentions that "performance characteristics for influenza A and B were established during January through March of 2011," implying a dataset used for development and validation. For the comparison between Veritor Reader and Veritor Plus Analyzer, the following samples were assessed:

• 102 Flu A-/B- samples
• 52 Flu A+ samples
• 52 Flu B+ samples

These samples were used to confirm equivalency between the interpreting instruments, not necessarily as a "training set" for the assay itself.

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

The document does not explicitly describe how the ground truth for any "training set" was established. However, given the context, it's highly probable that if a training set was used for algorithm development, the ground truth would also have been established by a highly sensitive and specific reference method like PCR or viral culture, similar to how the ground truth for the test set was established.

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The BD Veritor System for Rapid Detection of Flu A+B is a rapid chromatographic immunoassay for the direct and qualitative detection of influenza A and B viral nucleoprotein antigens from nasal and nasopharyngeal swabs of symptomatic patients. The BD Veritor System for Rapid Detection of Flu A+B (also referred to as the BD Veritor System and BD Veritor System Flu A+B) is a differentiated test, such that influenza A viral antigens can be distinguished from influenza B viral antigens from a single processed sample using a single device. The test is to be used as an aid in the diagnosis of influenza A and B viral infections. A negative test is presumptive and it is recommended that these results be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Outside the U.S., a negative test is presumptive and it is recommended that these results be confirmed by viral culture or a molecular assay cleared for diagnostic use in the country of use. FDA has not cleared this device for use outside of the U.S. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions. The test is not intended to detect influenza C antigens.

The BD Veritor™ Flu A+B test is an immunochromatographic assay for the qualitative detection of influenza A and B viral antigens in respiratory specimens. The patient specimen is mixed in a reaction tube prefilled with RV Reagent C, gently mixed, and then added to the test device. RV Reagent C contains mucolytic agents that function to break down mucus in a patient specimen thereby exposing viral antigens and enhancing detection in the assay device. Processed specimens are expressed through a filter tip into a single sample well on the BD Veritor™ Flu A+B test device.

After addition to the test device, any influenza A or influenza B viral antigens present in the specimen bind to anti-influenza antibodies conjugated to detector particles on the Veritor "" Flu A+B test strip. The antigen-conjugate complexes migrate across the test strip to the reaction area and are captured by a line of antibody striped on the membrane. The Veritor™ Flu A+B test devices are designed with five spatially-distinct zones including positive and negative control line positions, separate test line positions for the target analytes, and a background zone. The test lines for the target analytes are labeled on the test device as 'A' for Flu A position, and 'B' for Flu B position. The onboard positive control ensures the sample has flowed correctly and is indicated on the test device as 'C'. Two of the five distinct zones on the test device are not labeled. These two zones are an onboard negative control line and an assay background zone. The onboard negative control zone addresses non-specific signal generation. The remaining zone is used to measure the assay background.

The BD Veritor '™ Flu A+B assay incorporates an active negative control feature in each test to identify and compensate for sample-related, nonspecific signal generation. The BD Veritor™ System Reader uses a proprietary algorithm that subtracts nonspecific signal at the negative control line from the signal present at both the Flu A and Flu B test lines. If the resultant test line signal is above a pre-selected assay cutoff, the specimen scores as positive. If the resultant test line signal is below the cutoff, the specimen scores as negative. Use of the active negative control feature allows the BD Veritor ™ System reader to correctly interpret test results that cannot be scored visually because the human eye is unable to accurately perform the subtraction of the nonspecific signal.

Here's an analysis of the provided text, focusing on acceptance criteria and a study proving device performance, as per your request:

Acceptance Criteria and Reported Device Performance

The provided document is a 510(k) premarket notification for a CLIA-waived kit, specifically for a labeling change to add strain reactivity data. It does not contain detailed acceptance criteria for the initial device's performance or a full study report proving those criteria were met for the initial clearance. However, it does reference "Performance characteristics for influenza A and B were established during January through March of 2011".

Given that specific performance values (sensitivity, specificity, etc.) and explicit acceptance criteria are not presented in this document for the initial device clearance, I cannot create a table of acceptance criteria and reported device performance.

The new information being added to the labeling is strain reactivity data for specific influenza strains. This isn't a performance claim against a general population but rather a demonstration of the device's ability to detect particular viral subtypes.

Regarding the studies mentioned in the document:

This document describes an amendment to an already cleared device (BD Veritor System for Rapid Detection of Flu A + B CLIA waived Kit). The primary focus of this specific submission (K160161) is to add additional strain reactivity data to the labeling, not to re-evaluate the device's overall clinical performance.

The document states: "The labeling has been changed to reflect the addition of strain reactivity data for the following strains: A/Northern Pintail/Washington/40964/2014 (H5N2) and A/Gyrfalcon/Washington/41088-6/2014 (H5N8)." It explicitly notes that "Additions made to the labeling to add additional strain testing did not change the intended use of the device or the fundamental scientific technology."

Therefore, the "study" described or referenced in this particular document primarily pertains to:

• Strain Reactivity Testing: Testing the existing device with specific novel influenza strains (H5N2 and H5N8) to confirm detection and add this information to the labeling. Details of this specific testing (sample size, ground truth, etc.) are not provided in this document.

The document also refers to the original performance characteristics established in 2011: "Performance characteristics for influenza A and B were established during January through March of 2011 when influenza viruses A/2009 H1N1, A/H3N2, B/Victoria lineage were the predominant influenza viruses in circulation..." However, the details of that study are not provided here.

Based on the provided text, I can only address aspects relevant to the type of information requested, indicating when details are absent or not applicable to this specific submission.

1. A table of acceptance criteria and the reported device performance

   • Not provided in this document. This document focuses on supplemental strain reactivity data for an already cleared device, not the initial clinical performance metrics and acceptance criteria.

2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

   • For the new strain reactivity data (H5N2, H5N8): Not specified in this document.
   • For the original performance characteristics (2011): Not specified in this document. The document mentions "January through March of 2011" and predominant influenza viruses, suggesting a prospective or retrospective clinical study, but no details on sample size or data origin (country) are given here.

3. 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)

   • Not specified in this document. For influenza rapid tests, ground truth for clinical studies would typically be established by viral culture or a molecular assay, not human expert consensus like in imaging. For strain reactivity, it would be based on positive controls of the specific strains.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

   • Not applicable/Not specified. Adjudication methods are typically used when human interpretation of a diagnostic is the "ground truth" or part of the comparison. For assays like this, the reference method (e.g., PCR, viral culture) provides the definitive result.

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

   • Not applicable. This device is a rapid chromatographic immunoassay, not an AI-powered diagnostic that assists human readers. It's a standalone test with an optical reader.

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

   • Yes, this is a standalone device. The BD Veritor™ System Reader uses a proprietary algorithm to interpret the test strip results. The text describes this algorithm: "The BD Veritor™ System Reader uses a proprietary algorithm that subtracts nonspecific signal at the negative control line from the signal present at both the Flu A and Flu B test lines. If the resultant test line signal is above a pre-selected assay cutoff, the specimen scores as positive. If the resultant test line signal is below the cutoff, the specimen scores as negative." This is a automated interpretation without human intervention in the result reading process.

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

   • Not explicitly stated in this document for the original studies. For influenza diagnostics, the common ground truth methods are:
     • Viral Culture: Considered the "gold standard" for live virus detection.
     • FDA-cleared molecular assay (e.g., PCR): Highly sensitive and specific.
   • The "Indications for Use" section and "Intended Use" section state: "A negative test is presumptive and it is recommended that these results be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay." This strongly implies that these methods were used as the reference standard (ground truth) for the original performance evaluation.
   • For the new strain reactivity, the ground truth would be the known presence or absence of the specific influenza strains in controlled samples.

8. The sample size for the training set

   • Not specified in this document. The document discusses clinical performance characteristics and new strain reactivity, not the development of a machine learning model with distinct training/test sets in the AI sense. The "proprietary algorithm" for reading the strip would have been developed and "trained" on a dataset of test strip results, but details are not provided.

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

   • Not specified in this document. As mentioned above, this isn't an AI/ML development context where human experts label data for an algorithm. The "ground truth" for calibrating the reader's algorithm would be derived from known positive and negative samples, likely confirmed by a reference method like viral culture or PCR.

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