(133 days)
The cobas CT/NG v2.0 Test is an automated, in vitro nucleic acid amplification test for the qualitative detection of Chlamydia trachomatis (CT) and/or Neisseria gonormoeae (NG) DNA in urogenital specimens. The Test utilizes the Polymerase Chain Reaction (PCR) for the detection of Chiamydia trachomatis and Neisseria gonormoeae 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 PreservCyt® solution. This test is intended as an aid in the diagnosis of chlamydial and gonococcal disease in both symptomatic and asymptomatic individuals.
The changes between the previously cleared cobas® CT/NG Test (K110923) and the currently submitted cobas® CTNG v2.0 Test are limited to the modification of the sample preparation workflow which requires a system software update related to the cobas 4800 system. There are no changes for the reagents or the design between the cobas® CT/NG v2.0 Test and the cobas® CT/NG Test. The Roche Molecular Systems (RMS) cobas® CT/NG v2.0 Test consists of six reagent kits:
- cobas® 4800 System Sample Preparation Kit .
- cobas 4800 CT/NG v2.0 Amplification/Detection Kit .
- cobas® 4800 CT/NG Controls Kit .
- cobas 4800 System Wash Buffer Kit .
- cobas® 4800 System Control Diluent Kit .
- cobas® 4800 System Liquid Cytology Preparation Kit .
Sample Collection Kits to be used for the cobas CT/NG v2.0 Test are:
- cobas® PCR Female Swab Sample Kit •
- cobas® PCR Urine Sample Kit .
- PreservCyt® (Hologic, Inc.) .
The cobas® CTNG v2.0 Test for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) is based on two major processes: (1) automated sample preparation to obtain nucleic acids, including CT and NG DNA; (2) simultaneous PCR amplification of target DNA sequences using both CT and NG specific complementary primer pairs and real-time detection of cleaved fluorescent-labeled CT and NG specific oligonucleotide detection probes. Internal control. containing CT and NG DNA. is added to all samples during automated sample preparation and is amplified and detected simultaneously with each sample to monitor the entire process.
The cobas 4800 System utilizes the cobas x 480 Instrument for automated sample preparation, and the cobas z 480 Analyzer for automated amplification and detection. The cobas® 4800 system software integrates the sample preparation with nucleic acid amplification and detection to generate test results.
Here's a breakdown of the acceptance criteria and study details for the cobas® CT/NG v2.0 Test, based on the provided 510(k) summary:
1. Acceptance Criteria and Reported Device Performance
The acceptance criteria are implied by the reported performance metrics, primarily sensitivity and specificity, at various specimen types and symptom statuses. The device generally aims for high sensitivity and specificity.
Chlamydia trachomatis (CT) Clinical Performance
| Metric | Specimen Type (Gender) | Symptom Status | Acceptance Criteria (Implied) | Reported Performance (95% CI) |
|---|---|---|---|---|
| SENS | Endocervical Swabs (Female) | Overall | High | 94.9% (91.4%, 97.1%) |
| SENS | Urine (Female) | Overall | High | 94.0% (90.3%, 96.3%) |
| SENS | Clinician-collected Vaginal Swabs (Female) | Overall | High | 98.2% (94.9%, 99.4%) |
| SENS | Self-collected Vaginal Swabs (Female) | Overall | High | 97.6% (93.3%, 99.2%) |
| SENS | PreservCyt (Pre-aliquot) (Female) | Overall | High | 94.2% (90.4%, 96.5%) |
| SENS | PreservCyt (Post-aliquot) (Female) | Overall | High | 93.7%(89.8%, 96.1%) |
| SENS | Urine (Male) | Overall | High | 98.4% (94.2%, 99.5%) |
| SPEC | All Female Specimen Types | Overall | High | 99.1% - 99.7% |
| SPEC | Urine (Male) | Overall | High | 99.2% (98.1%, 99.7%) |
Neisseria gonorrhoeae (NG) Clinical Performance
| Metric | Specimen Type (Gender) | Symptom Status | Acceptance Criteria (Implied) | Reported Performance (95% CI) |
|---|---|---|---|---|
| SENS | Endocervical Swabs (Female) | Overall | High | 96.6% (90.6%, 98.8%) |
| SENS | Urine (Female) | Overall | High | 95.6% (89.1%, 98.3%) |
| SENS | Clinician-collected Vaginal Swabs (Female) | Overall | High | 100.0% (93.8%, 100.0%) |
| SENS | Self-collected Vaginal Swabs (Female) | Overall | High | 96.7% (83.3%, 99.4%) |
| SENS | PreservCyt (Pre-aliquot) (Female) | Overall | High | 96.7% (90.8%, 98.9%) |
| SENS | PreservCyt (Post-aliquot) (Female) | Overall | High | 95.6% (89.2%, 98.3%) |
| SENS | Urine (Male) | Overall | High | 100.0% (94.6%, 100.0%) |
| SPEC | All Female Specimen Types | Overall | High | 99.7% - 100.0% |
| SPEC | Urine (Male) | Overall | High | 99.3% (98.3%, 99.7%) |
2. Sample Size for the Test Set and Data Provenance
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Total Evaluable Subjects: 6,004 (5,266 females and 738 males)
-
Female Test Set Sub-samples:
- Endocervical Swabs (SW): 2926 (1932 symptomatic, 994 asymptomatic)
- Urine (UR): 2945 (1937 symptomatic, 1008 asymptomatic)
- Clinician-collected Vaginal Swabs (VG-C): 1902 (899 symptomatic, 1003 asymptomatic)
- Self-collected Vaginal Swabs (VG-S): 2037 (1041 symptomatic, 996 asymptomatic)
- PreservCyt (PC Pre): 2937 (1935 symptomatic, 1002 asymptomatic)
- PreservCyt (PC Post): 2878 (1871 symptomatic, 1007 asymptomatic)
-
Male Test Set Sub-samples:
- Urine (UR): 738 (278 symptomatic, 460 asymptomatic)
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Data Provenance: The studies were multi-center clinical investigations conducted in the United States.
- One clinical investigation used archived samples (endocervical specimens, self-collected and clinician collected vaginal specimens, endocervical specimens in PreservCyt Solution, and male and female urine specimens, from symptomatic and asymptomatic males and females) from the previous cobas® CT/NG Test evaluation.
- A second investigation used prospectively collected fresh samples (endocervical specimens, clinician-collected vaginal specimens, female urine specimens, and cervical specimens in PreservCyt Solution from asymptomatic women).
- Specimen collection took place at 18 collection sites in the US, including family planning, Obstetrics/Gynecology (OB/GYN) clinics, and sexually transmitted disease clinics.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not explicitly state the number of "experts" or their qualifications. The ground truth ("Patient Infected Status" - PIS) was established using a combination of results from two commercially available nucleic acid amplification tests (NAATs) (NAAT1 and NAAT2). These reference NAATs are implicitly considered the "expert" or gold standard. The qualifications of personnel performing these reference NAATs are not specified.
4. Adjudication Method for the Test Set
The adjudication method for establishing Patient Infected Status (PIS) was based on a "2+1" or consensus approach using two reference NAATs.
- A subject was categorized as infected for CT or NG if a minimum of two positive results (at least one from each reference NAAT) was reported.
- For CT only, female subjects with positive results on both reference urine specimens and negative results on both reference endocervical swab specimens and the reference cervical sample were categorized as infected for urine and not infected for swab specimens.
- A subject was classified as non-infected if at least one of the reference NAATs reported negative results for all sample types.
- Subjects were excluded if PIS could not be determined due to missing/indeterminate results from reference tests.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This study focuses on the standalone performance of the device (a diagnostic test kit), not on human reader performance with or without AI assistance. Therefore, there is no effect size of human readers improving with AI.
6. If a Standalone Study was done
Yes, a standalone performance study (algorithm only without human-in-the-loop performance) was done. The entire clinical performance section (Section 5) evaluates the cobas® CT/NG v2.0 Test directly against the established Patient Infected Status (PIS), which is derived from other NAATs, representing the algorithm's performance.
7. The Type of Ground Truth Used
The ground truth used was expert consensus (proxy by reference assays), specifically the Patient Infected Status (PIS), determined by the concordance of results from two commercially available predicate/reference Nucleic Acid Amplification Tests (NAATs).
8. The Sample Size for the Training Set
The document does not explicitly state a separate sample size for a training set. The language used ("clinical investigations") suggests that the samples described in Section 5.2 are primarily for performance evaluation and not necessarily a distinct, partitioned training set as might be found in machine learning contexts. However, the study does mention using archived samples from a previous clinical study of the cobas® CT/NG Test (K110923) combined with prospectively collected fresh samples for the current evaluation. It's possible the archived data contributed to various stages of development or internal validation, but a formal "training set" for the v2.0 device as a distinct phase with specified numbers is not detailed in this summary.
9. How the Ground Truth for the Training Set was Established
As a distinct "training set" is not explicitly defined, the method for establishing its ground truth is also not detailed. However, it's reasonable to infer that any data used in the development or internal validation phases would have relied on similar or equivalent methods for ground truth determination, likely involving comparison to established reference methods or culture, as is standard for diagnostic assay development. The summary focuses on the clinical performance evaluation of the final device using the PIS as described in point 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).