(87 days)
The cobas® CT/NG v2.0 Test is an automated, in vitro amplification test for the qualitative detection of Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG) DNA in urogenital specimens. The Test utilizes the Polymerase Chain Reaction (PCR) for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae DNA in male and female urine, self-collected vaginal swab specimens (collected in a clinical setting), clinician-collected vaginal swab specimens, and endocervical swab specimens, all collected in cobas® PCR Media (Roche Molecular Systems, Inc.), and cervical specimens collected in PreservCyte solution. This test is intended as an aid in the diagnosis of chlamydial and gonococcal disease in both symptomatic and asymptomatic individuals.
The cobas® CT/NG v2.0 Test is an automated, in vitro amplification test for the qualitative detection of Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG) DNA in urogenital specimens. The Test utilizes the Polymerase Chain Reaction (PCR) for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae DNA in male and female urine, self-collected vaginal swab specimens (collected in a clinical setting), clinician-collected vaginal swab specimens, and endocervical swab specimens, all collected in cobas® PCR Media (Roche Molecular Systems,, Inc.), and cervical specimens collected in PreservCvt® solution. The Test comprises of the assay and ancillary collection kits: (a) for female endocervical and vaginal swabs, and (b) for urine.
The changes to the previously cleared cobas® CT/NG v2.0 Test are limited to the modification of the original cobas® PCR Female Swab Sample Kit (now the cobas® PCR Media Dual Swab Sample Kit) to include one flocked endocervical swab and one spun bud swab, instead of two spun bud swabs. All the supporting clinical and analytical performance data, including stability data for specimens stabilized in the cobas® PCR Media, may be found under K132270. Additional data was generated, as described in Section 4 below, to demonstrate the substantial equivalence of the modified device to its predicate.
The modified cobas PCR Media Dual Swab Sample Kit is comprised of a collection medium tube and a packet containing two sterile swabs.
Kit Composition:
- cobas® PCR Media Dual Swab Sample Kit (1 spun bud swab and 1 flocked bud . swab)
- cobas® PCR Media 1 x 4.3 mL ●
Here's a breakdown of the acceptance criteria and the study details for the cobas® CT/NG v2.0 Test, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document focuses on demonstrating substantial equivalence to a predicate device (cobas® CT/NG v2.0 Test, K132270) rather than setting distinct, quantitative acceptance criteria for this specific submission (K163184). The changes in this submission are limited to the swab component of the collection kit. Therefore, the "acceptance criteria" here are implied to be non-inferiority or equivalent performance compared to the predicate device with its original swab.
| Acceptance Criteria (Implied) | Reported Device Performance (K163184 with new swab) |
|---|---|
| Equivalent Specimen Load / Analytical Sensitivity | Limiting Dilution LoD Determination: Limiting dilutions of specimens co-collected with the current/cleared swab and the new flocked swab exhibited consistent drop-out rates at similar levels when tested using the cobas® CT/NG v2.0 Test on the cobas® 4800 platform. "There was no indication that newly proposed flocked swab negatively impacted the analytical sensitivity of the test." |
| Clinical Performance (Positive/Negative Agreement) | Correlation Study with Clinical Specimens: |
- CT (Chlamydia trachomatis): PPA (Positive Percent Agreement) point estimate: 94.3%; NPA (Negative Percent Agreement): 99.7%; OPA (Overall Percent Agreement): 99.4%.
- NG (Neisseria gonorrhoeae): The 95% confidence interval for NG PPA encompasses 95%. (Specific point estimate not provided for NG PPA, but the statement implies acceptable performance relative to the predicate).
- Further statistical analyses of Ct values for positive concordant results demonstrated that specimens collected with the flocked swab are not significantly different from specimens collected with the woven swab. |
| Similar Technological Characteristics (for the assay itself) | The Intended Use, Sample Type, PCR Media, PCR Media Volume, Swab Number, Fiber Composition, and Shaft Composition of the submitted device are identical to the predicate device. The only differences are in Swab Type (1 Spun Bud and 1 Flocked Bud vs. 2 Spun Bud) and Bud Size (5.6 mm Diameter (Spun), 2.9 mm Diameter (Flocked) vs. 5.6 mm Diameter) due to the change in the collection kit. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: Not explicitly stated as a single number.
- For the limiting dilution LoD study, it involved "limiting dilutions of specimens."
- For the correlation study with clinical specimens, the percentages (PPA, NPA, OPA) imply a number of clinical samples were tested, but the exact count is not provided in this summary. It states "clinical specimens" without further detail on quantity or characteristics beyond being co-collected.
- Data Provenance: Not explicitly stated. The document indicates "clinical specimens," suggesting real-world samples, but doesn't specify country of origin, whether it was retrospective or prospective, or patient demographics.
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 summary. For an in vitro diagnostic device detecting microbial DNA, the "ground truth" is typically established by comparative methods (e.g., another FDA-cleared or well-validated NAAT, laboratory culture, or a composite reference standard) rather than human expert consensus on visual/imaging data.
4. Adjudication Method for the Test Set
- This information is not provided. Given the nature of a DNA amplification test, adjudication methods common in imaging (e.g., 2+1, 3+1) are usually not applicable. Ground truth for diagnostic tests often relies on predefined reference methods.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
- No, an MRMC comparative effectiveness study was not done. This type of study is primarily relevant for devices where human interpretation plays a significant role (e.g., medical imaging AI tools). The cobas® CT/NG v2.0 Test is an automated in vitro diagnostic device, where the result is determined by the instrument's detection of DNA, not human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
- Yes, the performance described is inherently standalone. The cobas® CT/NG v2.0 Test is an automated system for qualitative detection of DNA. The reported performance refers to the device's ability to detect CT/NG DNA in specimens using its PCR-based algorithm. There is no "human-in-the-loop" aspect to the DNA detection process itself.
7. The Type of Ground Truth Used
- The summary mentions "clinical specimens" and "limiting dilutions of specimens." For a diagnostic test, the ground truth for clinical performance is typically established by comparing the device's results to a composite reference standard (CRS) or a well-established, highly sensitive, and specific laboratory gold standard method (e.g., another CDC-validated NAAT or culture for NG) applied to the same or split clinical samples. The "PPA," "NPA," and "OPA" values are derived by comparing the test results against such a reference. The details of this gold standard are not explicitly described in this summary but would be present in the full submission (K132270) which underlies the "predicate device" performance.
8. The Sample Size for the Training Set
- This information is not provided in the K163184 summary. As this submission is primarily about a change in a collection component to an already cleared and trained device (cobas® CT/NG v2.0 Test K132270), the focus is on demonstrating non-inferiority with the new component, not new algorithm development or training. The original training data for K132270 would have been much larger.
9. How the Ground Truth for the Training Set Was Established
- This information is not provided in the K163184 summary. This would refer to how the original device (K132270) was developed and validated. Typically, for PCR-based in vitro diagnostics, the "training" involves optimizing primers, probes, and reaction conditions using well-characterized samples (often seeded with known quantities of target DNA) and comparing them against established reference methods for positive and negative controls.
§ 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).