Search Results

The BD ProbeTec Neisseria gonorrhoeae (GC) Q* Amplified DNA Assay, when tested with either the BD Viper™ System in Extracted Mode or the BD Viper™ LT System, uses Strand Displacement Amplification technology for the direct, qualitative detection of Neisseria gonorrhoeae DNA in clinician-collected female endocervical and male urethral swab specimens, patient-collected vaginal swab specimens (in a clinical setting), and male and female urine specimens (both UPT and Neat). The assay is also intended for use with gynecological specimens collected in BD SurePath™ Preservative Fluid or PreservCyt™ Solution using an aliquot that is removed prior to processing for either the BD SurePath or ThinPrep™ Pap test. The assay is indicated for use with asymptomatic and symptomatic individuals to aid in the diagnosis of gonococcal urogenital disease.

The BD ProbeTec GCO Assay is based on the simultaneous amplification and detection of target DNA using amplification primers and a fluorescently-labeled detector probe The reagents for strand displacement amplification (SDA) are dried in two separate disposable microwells: the Priming Microwell contains the amplification primers, fluorescently-labeled detector probe, nucleotides and other reagents necessary for amplification, while the Amplification Microwell contains the two enzymes (a DNA polymerase and a restriction endonuclease) that are required for SDA. In alignment with the FDA Guidance Document, "Assay Migration Studies for In Vitro Diagnostic Devices, Guidance for Industry and FDA Staff", April 25, 2013 the BD ProbeTec GCQ Assay is being migrated from the existing BD Viper System operating in extracted mode (Viper XTR) to the new BD Viper LT System.

The BD Viper LT System is a table-top instrument that is designed to be fully contained on a standard laboratory bench-top. The system performs automated extraction of nucleic acids from multiple specimen types in addition to amplification and detection of target nucleic acid sequences when utilized with legally marketed in vitro diagnostic assays.

Here's a summary of the acceptance criteria and study details for the BD ProbeTec™ Neisseria gonorrhoeae (GC) Q* Amplified DNA Assay on the BD Viper LT System, based on the provided text:

Acceptance Criteria and Device Performance

The general acceptance criteria for this type of diagnostic device is that the performance on the new system (BD Viper LT) should be substantially equivalent to the predicate device (BD Viper System in Extracted Mode), which implies comparable Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA). While explicit numerical acceptance criteria for PPA and NPA are not stated in the document, the clinical study results are presented to demonstrate this equivalence. The analytical performance (system contamination rate and reproducibility) also contributes to the overall equivalence determination.

• Female (All specimen types): 97.9% (320/327) with 95% CI (95.1%, 100.0%)
• Male (Q*UPT): 100.0% (120/120)
• Overall (All): 98.4% (440/447) with 95% CI (96.4%, 100.0%)

Negative Percent Agreement (NPA):

• Female (All specimen types): 98.8% (934/945) with 95% CI (97.9%, 99.6%)
• Male (Q*UPT): 99.5% (218/219) with 95% CI (98.6%, 100.0%)
• Overall (All): 99.0% (1152/1164) with 95% CI (98.1%, 99.6%) |
  | Analytical Performance | System Contamination Rate:
• Q* Swab Diluent: 0.32% (2/630)
• LBC Specimen Matrix: 0.0% (0/630)

Reproducibility (Overall for various specimen types and panels):

• LBC: % Correct between 20.8% (High Negative) and 100.0% (Negative, Low Positive, Moderate Positive)
• Swab: % Correct between 13.5% (High Negative) and 100.0% (Negative, Low Positive, Moderate Positive)
• UPT: % Correct between 18.8% (High Negative) and 100.0% (Negative, Low Positive, Moderate Positive)
• Overall %CVs range from 9.1% to 433.8% (for negative/high negative where the mean is very low and thus %CV can be high) for quantitation, but 100% agreement for positive controls. |

Study Details

1. Sample size used for the test set and the data provenance:

   • Clinical Performance Test Set:
     • Female subjects: 617 compliant subjects
     • Male subjects: 167 compliant subjects
     • Total Clinical Samples: A total of 327 positive and 945 negative results for females across various specimen types were evaluated on the BD Viper LT system. For males, 120 positive and 219 negative results were evaluated for Q*UPT.
     • Data Provenance: The specimens were collected prospectively from individuals attending OB/GYN, sexually transmitted disease (STD), and family planning clinics at four geographically diverse clinical sites in North America. These were then assembled into comparison panels at BD and shipped to test sites.
   • Analytical Performance Test Set:
     • System Contamination: 630 Negative samples (Q* Swab Diluent or LBC Specimen Matrix) and 630 Positive samples (spike GC at 10^3 CT EB/mL) per matrix type (Q* Swab Diluent, LBC Specimen Matrix). Tested on three BD Viper LT Systems.
     • Reproducibility: 3 levels of CT and GC organisms (and negative controls) seeded into LBC specimen matrix, vaginal matrix in Q* Swab Diluent, and urine specimen matrix. Two operators per site ran one panel each day for 8 days, totaling 16 runs. Each run consisted of 8 LBC, 8 swab, and 8 UPT panel members. This means for each panel type (LBC, Swab, UPT) and each level (Negative, High Negative, Low Positive, Moderate Positive), there were 96 replicates (3 sites * 2 operators * 8 days * 2 replicates per panel member or 3 sites * 16 runs * 2 replicates per panel member).

2. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
   The ground truth for the clinical performance study was established by the BD Viper System in extracted mode reference results (the predicate device). It's not explicitly stated that human experts were involved in establishing the ground truth for each individual case in the test set. Instead, the predicate device itself served as the reference standard for comparison. The document does not specify the number or qualifications of experts directly used to establish this "ground truth" beyond relying on the previously cleared predicate device.

3. Adjudication method for the test set:
   The document states: "Each comparison panel consisted of randomly chosen positive and negative specimens (based on BD Viper System in extracted mode reference results). The positive and negative specimens were randomized within the panel, and labeled such that the instrument user was blinded to the specimen results." This implies that the results from the BD Viper LT System were compared against the established reference results from the predicate BD Viper System. There is no mention of a human expert adjudication method (e.g., 2+1, 3+1) for discordant results between the new device and the predicate device. The comparison appears to be direct.

4. 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. This device is a molecular diagnostic assay (NAAT) for the detection of Neisseria gonorrhoeae DNA, not an imaging device requiring human reader interpretation. Therefore, the concept of "human readers improving with AI vs without AI assistance" is not applicable in this context. The assay provides a qualitative "positive" or "negative" result.

5. If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
   Yes, the device's performance is standalone. The BD ProbeTec GCQ Assay on the BD Viper LT System is an automated instrument that performs nucleic acid extraction, amplification, and detection. It provides a qualitative result ("positive" or "negative") directly. Human involvement is in specimen collection, loading the samples, and interpreting the final automated result from the instrument, but not in the analytical process of generating the result itself. The clinical performance study directly compares the results of this automated system to the predicate automated system.

6. The type of ground truth used (expert consensus, pathology, outcomes data, etc):
   The ground truth for the clinical performance comparison was the results from the predicate device: the BD ProbeTec GCQ Assay on the BD Viper System in Extracted Mode. This type of ground truth is often referred to as a "reference method" or "comparator method" in device migration studies. While the predicate device itself would have initially been cleared against a gold standard (e.g., culture or a combination of clinical outcomes and other diagnostic tests), for this 510(k) submission, the predicate device serves as the established "truth" for demonstrating substantial equivalence of the new system for the same assay.

7. The sample size for the training set:
   The document does not explicitly state the sample size used for a "training set." This submission focuses on the migration of an existing assay formulation to a new instrument system. The assay formulation itself has "not changed." Therefore, it is implied that the assay was developed and "trained" (in a molecular biology sense, not necessarily machine learning) prior to this study on the new platform. The data provided are for analytical verification and a clinical comparison study.

8. How the ground truth for the training set was established:
   As there is no distinct "training set" described in the context of machine learning, the concept of establishing ground truth for it is not applicable here. The assay formulation itself was developed based on established molecular biology principles for detecting Neisseria gonorrhoeae DNA. The ground truth for the predicate device (K081825) would have been established through its own clinical trials, likely using culture as a primary reference standard, possibly augmented by discrepant analysis with other methods. For this K140448 submission, the primary ground truth for comparison is the performance of the predicate device itself.

Ask a specific question about this device

The BD ProbeTec™ Neisseria gonorrhoeae (GC) Q* Amplified DNA Assay, when tested with the BD Viper™ System in Extracted Mode, uses Strand Displacement Amplification technology for the direct, qualitative detection of Neisseria gonorrhoeae DNA in clinician-collected female endocervical and male urethral swab specimens, patient collected vaginal swab specimens (in a clinical setting), and male and female urine specimens (both UPT and Neat). The assay is also intended for use with gynecological specimens collected in BD SurePath™ Preservative Fluid using an aliquot that is removed prior to processing for the BD SurePath™ Pap test. The assay is indicated for use with asymptomatic and symptomatic individuals to aid in the diagnosis of gonococcal urogenital disease.

The BD ProbeTec GC Q* Amplified DNA Assay is based on the simultaneous amplification and detection of target DNA using amplification primers and a fluorescently-labeled detector probe. The reagents for SDA are dried in two separate disposable microwells: the Priming Microwell contains the amplification primers, fluorescently-labeled detector probe, nucleotides and other reagents necessary for amplification, while the Amplification Microwell contains the two enzymes (a DNA polymerase and a restriction endonuclease) that are required for SDA. The BD Viper 10 System pipettes a portion of the purified DNA solution from each Extraction Tube into a Priming Microwell to rehydrate the contents. After a brief incubation, the reaction mixture is transferred to a corresponding, pre-warmed Amplification Microwell which is sealed to prevent contamination and then incubated in one of the two thermally-controlled fluorescent readers. The presence or absence of N. gonorrhoeae DNA is determined by calculating the peak fluorescence (Maximum Relative Fluorescent Units (MaxRFU)) over the course of the amplification process and by comparing this measurement to a predetermined threshold value.

In addition to the fluorescent probe used to detect amplified N. gonorrhoeae target DNA, a second labeled oligonucleotide is incorporated in each reaction. The Extraction Control (EC) oligonucleotide is labeled with a different dye than that used for detection of the N. gonorrhoeae -specific target and is used to confirm the validity of the extraction process. The EC is dried in the Extraction Tubes and is rehydrated upon addition of the specimen and extraction reagents. At the end of the extraction process, the EC fluorescence is monitored by the BD Viper System and an automated algorithm is applied to both the EC and N. gonorrhoede -specific signals to report results as positive, negative, or EC failure.

Here's an analysis of the BD ProbeTec™ Neisseria gonorrhoeae (GC) Q* Amplified DNA Assay based on the provided document, focusing on acceptance criteria and supporting study details:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state pre-defined "acceptance criteria" in a numerical format that the device must meet. Instead, it presents the results of its clinical performance study and concludes that these results "support the determination of substantial equivalence." Therefore, the reported performance itself, particularly sensitivity and specificity, serves as the de-facto measure of whether the device is considered acceptable for its intended use.

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

• Sample Size (Clinical Performance):
  • Female Subjects: 1728 compliant female subjects enrolled, 1715 included in final data analysis.
  • Specimens:
    • 3 randomized endocervical swab specimens per subject (for reference methods).
    • 1 BD SurePath specimen per subject (for the device under evaluation).
• Data Provenance:
  • Country of Origin: North America (specifically, "eleven geographically diverse clinical sites in North America").
  • Retrospective or Prospective: The study describes specimen collection from "subjects attending family planning, OB/GYN, and sexually transmitted disease clinics," implying a prospective collection for the purpose of this study.

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

The document does not mention the use of "experts" to establish ground truth in the traditional sense of a human review panel. Instead, the ground truth was established using a Patient Infected Status (PIS) algorithm rather than expert consensus on individual cases.

4. Adjudication Method for the Test Set

The adjudication method for establishing the Patient Infected Status (PIS) was algorithmic, not human adjudication:

• Method: A PIS algorithm based on the results of three reference endocervical swab methods:
  • BD ProbeTec ET CT/GC/AC assay
  • BD ProbeTec GC Q* assay (the predicate device)
  • Another commercially available NAAT (Nucleic Acid Amplification Test)
• Criteria:
  • PIS-positive: At least two positive reference results were required.
  • PIS-negative: At least two negative reference results were required.

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

No, an MRMC comparative effectiveness study involving human readers with and without AI assistance was not done. This device is an in vitro diagnostic (IVD) assay that directly detects DNA using a machine (BD Viper System), not an image-based AI system that assists human interpretation.

6. Standalone Performance

Yes, the study primarily evaluates the standalone performance of the BD ProbeTec GC Q* Amplified DNA Assay integrated with the BD Viper System. The clinical performance table (Table 4) presents the sensitivity and specificity of the device against the "Patient Infected Status" (ground truth). This is the algorithm's performance without a human in the loop interpreting the results, as the output is a "positive, negative, or EC failure."

7. Type of Ground Truth Used

The ground truth used was a Patient Infected Status (PIS) algorithm derived from the results of multiple established reference Nucleic Acid Amplification Tests (NAATs) on endocervical swab specimens. While not direct pathology (like tissue biopsy), it represents a "composite reference standard" or "latent class analysis" approach, which is common and often considered highly accurate for infectious disease diagnostics when a single gold standard is imperfect or invasive.

8. Sample Size for the Training Set

The document does not explicitly state the sample size for a "training set." This is typical for in vitro diagnostic assays like this one. Unlike machine learning algorithms that require distinct training and test sets, the development of IVD assays often involves an iterative process of reagent optimization and analytical validation (LOD, interference, etc.) using spiked samples and smaller initial specimen panels, followed by a larger, independent clinical validation set (which is what is described here). The "training" in this context refers to the development and optimization of the assay itself and its algorithm, which is not typically quantified by a specific "training set" sample size in the same way an AI model would be.

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

As noted above, a distinct "training set" with a formally established ground truth, as understood in machine learning, is not described for this IVD assay. The development and optimization of the assay's internal algorithms (e.g., for calculating MaxRFU and applying the automated algorithm for positive/negative/EC failure) would have been based on analytical studies and perhaps smaller, internal clinical sample sets where results were correlated with known positive and negative samples, often confirmed by reference methods or culture. The document focuses on the validation of the final assay on a robust clinical test set.

Ask a specific question about this device

The BD ProbeTect™ Neisseria gonorrhoeae (GC) Q* Amplified DNA Assay, when tested with the BD Viper™ System in extracted mode, uses Strand Displacement Amplification (SDA) technology for the direct, qualitative detection of Neisseria gonorrhoeae DNA in cliniciancollected female endocervical and male urethral swabs, patient-collected vaginal swab specimens (in a clinical setting), and female and male urine specimens. The assay is indicated for use with asymptomatic and symptomatic female and male individuals to aid in the diagnosis of gonococcal urogenital disease.

The BD Viper System, when used with the BD ProbeTec amplified nucleic assay(s), is intended for the in vitro detection of targeted organisms from specimens as identified in the assay-specific reagent package insert(s).

The BD ProbeTec GC Q* Amplified DNA Assay is based on the simultaneous amplification and detection of target DNA using amplification primers and a fluorescently-labeled detector probe. The reagents for SDA are dried in two separate disposable microwells: the Priming Microwell contains the amplification primers, fluorescently-labeled detector probe, nucleotides and other reagents necessary for amplification. while the Amplification Microwell contains the two enzymes (a DNA polymerase and a restriction endonuclease) that are required for SDA. The BD Viper "M System pipettes a portion of the purified DNA solution from each Extraction Tube into a Priming Microwell to rehydrate the contents. After a brief incubation, the reaction mixture is transferred to a corresponding, pre-warmed Amplification Microwell which is sealed to prevent contamination and then incubated in one of the two thermally-controlled fluorescent readers. The presence or absence of N. gonorrhoeae DNA is determined by calculating the peak fluorescence (Maximum Relative Fluorescent Units (MaxRFU)) over the course of the amplification process and by comparing this measurement to a predetermined threshold value.

In addition to the fluorescent probe used to detect amplified N. gonorrhoeae target DNA, a second labeled oligonucleotide is incorporated in each reaction. The Extraction Control (EC) oligonucleotide is labeled with a different dye than that used for detection of the N. gonorrhoeae -specific target and is used to confirm the validity of the extraction process. The EC is dried in the Extraction Tubes and is rehydrated upon addition of the specimen and extraction reagents. At the end of the extraction process, the EC fluorescence is monitored by the BD Viper System and an automated algorithm is applied to both the EC and N. gonorrhoeae -specific signals to report results as positive, negative, or EC failure.

Here's an analysis of the acceptance criteria and study detailed in the provided text for the BD ProbeTec™ Neisseria gonorrhoeae (GC) Q* Amplified DNA Assay:

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are implied by the clinical performance results, where high sensitivity and specificity are demonstrated across various specimen types and patient asymptomatic/symptomatic statuses. While explicit numerical acceptance criteria (e.g., "sensitivity must be >95%") are not explicitly stated as 'acceptance criteria' in the document, we can infer the achieved performance as the criteria met for substantial equivalence.

A = Asymptomatic, S = Symptomatic

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

• Sample Size for Test Set:
  • Female subjects: 994 (eligible)
  • Male subjects: 774 (eligible)
  • Total BD ProbeTec GC Q* assay results used for performance calculations: 6284
• Data Provenance:
  • Country of Origin: North America (seven geographically diverse clinical sites).
  • Retrospective or Prospective: Prospective. The study involved collecting various specimens (endocervical swabs, male urethral swabs, vaginal swabs, and urine) from symptomatic and asymptomatic subjects.

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

Explicit details on the number of experts or their qualifications (e.g., radiologist with 10 years of experience) for establishing ground truth are not provided. The ground truth was established using an algorithm based on results from two commercially available Nucleic Acid Amplification Tests (NAATs) (the BD ProbeTec ET GC/AC assay and another commercially available NAAT). This method relies on the established performance of these reference NAATs rather than individual expert review of each case.

4. Adjudication Method for the Test Set

The adjudication method used to establish the "patient infected status" (PIS) for the ground truth was a 2-out-of-N rule (where N refers to the number of reference tests performed).

• For Female subjects (endocervical swab and urine specimens): Subjects were considered infected if "two of the four endocervical swab and urine specimens (or two of the three or four urethral swab and urine specimens) tested positive in the BD ProbeTec ET GC/AC assay and the other reference NAAT (one specimen testing positive in each NAAT)."
• For Male subjects (urethral swab and urine specimens): Similar algorithm applied.
• Non-infected: Subjects were considered non-infected if "less than two reference NAAT results were positive."

This implies specimens were tested by at least two reference NAATs (BD ProbeTec ET GC/AC and another commercial NAAT).

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

No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This study evaluates the performance of an assay (device) directly against a ground truth, not the comparative improvement of human readers with or without AI assistance. The device is for direct detection of N. gonorrhoeae DNA, not for aiding human interpretation of images or other data.

6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study

Yes, a standalone study was performed. The BD ProbeTec GC Q* Amplified DNA Assay is a fully automated system that detects N. gonorrhoeae DNA and reports results as positive, negative, or EC failure. The performance data presented (sensitivity and specificity) is based on the algorithm's direct output compared to the established patient infected status, without human intervention in result interpretation. The "BD Viper™ System and an automated algorithm is applied to both the EC and N. gonorrhoeae -specific signals to report results."

7. Type of Ground Truth Used

The ground truth used was a composite reference standard or patient infected status (PIS) algorithm, derived from the results of two different commercially available Nucleic Acid Amplification Tests (NAATs): the BD ProbeTec ET GC/AC assay and another commercially available NAAT. It is based on the concordance of these reference molecular tests, rather than pathology (histology), expert consensus of clinical symptoms, or long-term outcomes data.

8. Sample Size for the Training Set

The document does not explicitly state a separate training set size. The clinical performance characteristics are reported from a single clinical study dataset. In diagnostic assay development, initial algorithm development and optimization might occur using internal datasets, but this document describes the validation study for regulatory submission. It's common in IVD submissions for the entire clinical study population to be used for performance evaluation against the ground truth without a separate "training set" as understood in machine learning (where the algorithm learns from the data). If an algorithm's parameters were tuned on this specific dataset, it would be a form of internal validation rather than a truly independent test set. However, the text focuses on the device's performance measurement, implying that the algorithm's parameters were fixed by the time this validation study was conducted.

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

As noted above, a separate "training set" is not explicitly mentioned. For the test set, the ground truth was established by a patient infected status (PIS) algorithm based on the concordance of two distinct commercially available NAATs (BD ProbeTec ET GC/AC assay and another commercially available NAAT) on various patient specimens.

Ask a specific question about this device

The BD ProbeTec™ Neisseria gonorrhoeae (GC) O* Amplified DNA Assay, when tested with the BD Viper™ System in Extracted Mode, uses Strand Displacement Amplification technology for the direct, qualitative detection of Neisseria gonorrhoeae DNA in clinician-collected female endocervical and male urethral swab specimens, patient-collected vaginal swab specimens (in a clinical setting), and male and female urine specimens (both UPT and Neat). The assay is also intended for use with gynecological specimens collected in PreservCyt® Solution using an aliquot that is removed prior to processing for additional gynecological testing. The assay is indicated for use with asymptomatic females and symptomatic males to aid in the diagnosis of gonococcal urogenital disease.

The BD Viper System, when used with the BD ProbeTec amplified nucleic assay(s), is intended for the in vitro detection of targeted organisms from specimens as identified in the assay-specific reagent package insert(s).

The BD ProbeTec GC Q* Amplified DNA Assay is based on the simultaneous amplification and detection of target DNA using amplification primers and a fluorescently-labeled detector probe. The reagents for SDA are dried in two separate disposable microwells: the Priming Microwell contains the amplification primers, fluorescently-labeled detector probe, nucleotides and other reagents necessary for amplification, while the Amplification Microwell contains the two enzymes (a DNA polymerase and a restriction endonuclease) that are required for SDA. The BD Viper TM System pipettes a portion of the purified DNA solution from each Extraction Tube into a Priming Microwell to rehydrate the contents. After a brief incubation, the reaction mixture is transferred to a corresponding, pre-warmed Amplification Microwell which is sealed to prevent contamination and then incubated in one of the two thermally-controlled fluorescent readers. The presence or absence of N. gonorrhoeae DNA is determined by calculating the peak fluorescence (Maximum Relative Fluorescent Units (MaxRFU)) over the course of the amplification process and by comparing this measurement to a predetermined threshold value.

In addition to the fluorescent probe used to detect amplified N. gonorrhoeae target DNA, a second labeled oligonucleotide is incorporated in each reaction. The Extraction Control (EC) oligonucleotide is labeled with a different dye than that used for detection of the N. gonorrhoeae -specific target and is used to confirm the validity of the extraction process. The EC is dried in the Extraction Tubes and is rehydrated upon addition of the specimen and extraction reagents. At the end of the extraction process, the EC fluorescence is monitored by the BD Viper System and an automated algorithm is applied to both the EC and N. gonorrhoeae -specific signals to report results as positive, negative, or EC failure.

The provided document describes the clinical performance and analytical characteristics of the BD ProbeTec™ Neisseria gonorrhoeae (GC) Q* Amplified DNA Assay.

Here's an analysis of the acceptance criteria and study details:

1. Table of Acceptance Criteria and Reported Device Performance:

The document doesn't explicitly state numeric "acceptance criteria" in a dedicated section with pass/fail thresholds. Instead, it presents the assay's performance characteristics. For this table, I will infer the implied acceptance standard is demonstrating high sensitivity and specificity for the detection of N. gonorrhoeae.

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

• Sample Size (Clinical Test Set): 2074 female subjects were evaluated with PreservCyt specimens. This was after excluding 2 subjects with undetermined patient infected status and 3 subjects without a PreservCyt specimen result from an initial 2079 compliant subjects.
• Data Provenance:
  • Country of Origin: North America (specifically, eleven geographically diverse clinical sites).
  • Retrospective or Prospective: The study was prospective, involving the collection of specimens from subjects attending family planning, OB/GYN, and sexually transmitted disease clinics. Subjects were classified as symptomatic or asymptomatic based on reported symptoms at the time of collection.

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 or qualifications of individual experts. The "ground truth" (Patient Infected Status, PIS) was established algorithmically based on the results of three reference methods performed on three randomized endocervical swab specimens. These reference methods were:

• BD ProbeTec ET CT/GC/AC assay
• BD ProbeTec GC Q assay
• Another commercially available NAAT (Nucleic Acid Amplification Test)

4. Adjudication Method for the Test Set:

The adjudication method for establishing the Patient Infected Status (PIS) was an algorithmic consensus method:

• PIS-Positive: At least two positive reference results were required.
• PIS-Negative: At least two negative reference results were required.

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

No, a multi-reader multi-case (MRMC) comparative effectiveness study was not performed or described. This assay is a diagnostic test performed by an automated system (BD Viper System), not an imaging device requiring human interpretation of results in a comparative effectiveness setting.

6. Standalone (Algorithm Only) Performance:

Yes, the study describes the standalone performance of the BD ProbeTec GC Q* Amplified DNA Assay. The clinical performance characteristics (sensitivity, specificity) are reported for the assay's results compared to the established patient infected status, without human-in-the-loop interpretation impacting the reported performance metrics of the device itself. The BD Viper System applies an automated algorithm to report results as positive, negative, or EC failure.

7. Type of Ground Truth Used:

The ground truth used was expert consensus (algorithmic) based on the results of multiple predicate/reference nucleic acid amplification tests (NAATs). Specifically, a Patient Infected Status (PIS) algorithm was used, requiring at least two positive or two negative results from three different reference NAATs to classify a subject as PIS-positive or PIS-negative, respectively. It is not pathology, or direct outcomes data, but rather a derived "patient infected status" based on highly sensitive and specific laboratory tests.

8. Sample Size for the Training Set:

The document does not provide information on the sample size used for the training set. Standard practice for such assays typically involves extensive internal development and optimization (which would constitute "training") but explicit details on a distinct "training set" are not always presented in 510(k) summaries, which often focus on formal validation data.

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

The document does not describe how the ground truth for any training set might have been established. As mentioned above, details about a separate "training set" are absent from this summary.

Ask a specific question about this device