(78 days)
The APTIMA® Assay for Neisseria gonorrhoeae is a target amplification nucleic acid probe test that utilizes target capture for the in vitro qualitative detection of ribosomal RNA (rRNA) from Neisseria gonorrhoeae (GC) to aid in the diagnosis of gonococcal urogenital disease. The assay may be used to test the following specimens from symptomatic individuals: clinician-collected endocervical, vaginal and male urethral swab specimens; and female and male urine specimens. The assay may be used to test the following specimens from asymptomatic individuals: cliniciancollected endocervical and vaginal swab specimens; and patient-collected vaginal swab specimens and female and male urine specimens. The assay is also intended for use with the testing of gynecological specimens, from both symptomatic and asymptomatic patients, collected in the PreservCyt Solution and processed with the Cytyc ThinPrep 2000 System.
Clearance of this premarket notification extends the clinical performance claims of the commercially available GEN-PROBE APTIMA Assay for Neisseria gonorrhoeae to include PreservCyt liquid Pap specimens (collected and processed by the Cytyc ThinPrep 2000 Processor) as acceptable testing specimens. The ancillary kit formulated for this specific application is the commercially available GEN-PROBE APTIMA Specimen Transfer Kit. The components of the APTIMA Specimen Transfer Kit include: (1) a transport tube containing transport media with a penetrable cap and (2) specific instructions for use regarding decontamination and specimen processing procedures. The APTIMA Specimen Transfer Kit may only be used in conjunction with GEN-PROBE APTIMA Assays for the detection of Chlamydia trachomatis and/or Neisseria gonorrhoeae.
The provided document describes the GEN-PROBE APTIMA Assay for Neisseria gonorrhoeae, specifically its expanded indication for use with ThinPrep Specimens. The acceptance criteria and the study proving the device meets these criteria are detailed below.
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for sensitivity and specificity are not explicitly stated as numerical targets in the document. However, the study results are presented as the "Summary of Clinical Performance Data" and indicate the device's performance attributes. The general expectation for such a diagnostic assay is high sensitivity and specificity. The reported performance is based on the clinical study.
| Metric | Acceptance Criteria (Implied / Not Explicitly Stated) | Reported Device Performance (Overall) |
|---|---|---|
| Sensitivity | High sensitivity expected | 92.3% (12/13) |
| Specificity | High specificity expected | 99.8% (1630/1633) |
2. Sample Sizes and Data Provenance
- Test Set Sample Size: 1,646 symptomatic and asymptomatic female subjects were evaluated in the clinical study. (Page 8)
- Data Provenance: The data was collected from a prospective multi-center clinical study (Page 8). The study subjects were enrolled from sites with GC prevalence ranging from 0.0% to 5.0% (Page 8). While the exact country of origin is not explicitly stated, the context of an FDA submission (K062440) for a device from "San Diego, California" implies the study was likely conducted in the United States.
3. Number of Experts and Qualifications for Ground Truth
The document does not mention the use of experts to establish ground truth for the clinical study.
4. Adjudication Method for the Test Set
The adjudication method used to establish the "patient infected status" (ground truth) for the clinical study was based on a reference standard involving two other tests:
- The APTIMA Combo 2 Assay (for Chlamydia trachomatis and Neisseria gonorrhoeae).
- The APTIMA GC Assay (performed on endocervical swab specimens). (Page 8)
The criteria were:
- Infected Patient Status: Both reference NAATs (APTIMA Combo 2 Assay and APTIMA GC Assay on endocervical swab) were required to be positive.
- Non-Infected Patient Status: At least one reference NAAT was required to be negative.
- Inconclusive: If an equivocal result was obtained from any one of the reference NAATs, the patient infected status was categorized as inconclusive, and these specimens were not included in sensitivity and specificity calculations. (Page 8)
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study was mentioned. The study focuses on the performance of the device itself against a defined ground truth, not on human readers with or without AI assistance.
6. Standalone Performance
Yes, a standalone (algorithm only) performance study was performed. The clinical study directly evaluated the performance of the APTIMA GC Assay in PreservCyt liquid Pap specimens against a defined patient infected status (ground truth) derived from other laboratory tests, without human-in-the-loop performance described. (Page 8)
7. Type of Ground Truth Used
The ground truth used was based on a composite reference standard derived from the results of two other Nucleic Acid Amplification Tests (NAATs) – the APTIMA Combo 2 Assay and the APTIMA GC Assay – performed on endocervical swab specimens. Specifically, two positive reference NAATs defined an infected patient, and at least one negative defined a non-infected patient. (Page 8)
8. Sample Size for the Training Set
The document does not explicitly mention a separate "training set" or its sample size for model development. Diagnostic assays like this typically undergo extensive analytical validation to determine performance characteristics (e.g., limit of detection, specificity) and then clinical validation using a distinct clinical sample set. The analytical studies describe testing with various organisms and dilutions, which might be considered part of the development and refinement process, but not a formally delineated "training set" in the context of machine learning.
9. How Ground Truth for the Training Set Was Established
Since a distinct "training set" is not described, the method for establishing its ground truth is not provided. For the analytical studies (e.g., Limit of Detection, Analytical Specificity), organism concentrations were precisely controlled by direct comparison/dilution of clinical isolates or by spiking known concentrations of organisms/cells into samples. (Page 3-4)
§ 866.3390
Neisseria spp. direct serological test reagents.(a)
Identification. Neisseria spp. direct serological test reagents are devices that consist of antigens and antisera used in serological tests to identifyNeisseria spp. from cultured isolates. Additionally, some of these reagents consist ofNeisseria spp. antisera conjugated with a fluorescent dye (immunofluorescent reagents) which may be used to detect the presence ofNeisseria spp. directly from clinical specimens. The identification aids in the diagnosis of disease caused by bacteria belonging to the genusNeisseria, such as epidemic cerebrospinal meningitis, meningococcal disease, and gonorrhea, and also provides epidemiological information on diseases caused by these microorganisms. The device does not include products for the detection of gonorrhea in humans by indirect methods, such as detection of antibodies or of oxidase produced by gonococcal organisms.(b)
Classification. Class II (performance standards).