(115 days)
The Abbott RealTime CT/NG assay is an in vitro polymerase chain reaction (PCR) assay for the direct, qualitative detection of the plasmid DNA of Chlamydia trachomatis and the genomic DNA of Neisseria gonorrhoeae. The assay may be used to test the following specimens from symptomatic individuals: clinician-collected vaginal swab and male urethral swab specimens; patient-collected vaginal swab specimens; and female and male urine specimens. The assay may be used to test the following specimens from asymptomatic individuals: male and female urine.
The Abbott multi-Collect Specimen Collection Kit is intended for the collection and transportation of malc and female swab and urine specimens for the detection of Chlamydia trachomatis and Neisseria gonorrheae per instructions provided.
Self-collected vaginal swab specimens are an option for screening women when a pelvic exam is not otherwise indicated. The Abbott multi-Collect Specimen Collection Kit is not intended for home use.
Abbott RealTime CT/NG consists of two reagent kits:
- . Abbott RealTime CT/NG Amplification Reagent Kit (List No. 8L07-90)
- Abbott RealTime CT/NG Control Kit (List No. 8L07-80) .
The Abbott RealTime CT/NG assay uses PCR technology with homogenous real-time fluorescence detection on the m2000 System. The Abbott m2000 System consists of the Abbott m2000sp and Abbott m2000rt instruments. The Abbott m2000 System integrates sample preparation with nucleic acid amplification and detection to generate assay rcsults. The Abbott m2000sp is used for processing samples and the Abbott m2000rt is used for amplification and detection.
The Abbott multi-Collect Specimen Collection Kit can be used to collect either a swab or a urine specimen. Each Abbott multi -Collect Specimen Collection Kit (List No. 9K12) contains:
- One Transport Tube containing 1.2 mL Specimen Transport Buffer .
- . One Individually Packaged Sterile Specimen Collection Swab (Part No. CD650)
- . One disposable transfer pipette.
The Specimen Transport Buffer consists of guanidine thiocyanate, a chaotropic salt, in Tris buffer and is used to stabilize DNA until sample preparation. The individually packaged sterile Specimen Collection Swab is used for swab sample collection and placed directly into the Transport Tube. The transfer pipette is used to add approximately 3 mL of urine to the Transport Tube. The Abbott multi -Collect Specimen Collection Kit is for single use only.
Here's an analysis of the acceptance criteria and supporting studies for the Abbott RealTime CT/NG assay and Abbott multi-Collect Specimen Collection Kit, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for this device are implied by the reported clinical performance. The goal is to achieve high sensitivity and specificity compared to reference methods. The specific acceptance thresholds are not explicitly stated as numerical targets for sensitivity and specificity in the provided text, but the reported performance values are presented as demonstrating effective detection.
| Test Type | Organism | Specimen Type | Acceptance Criteria (Implied) | Reported Device Performance (Sensitivity (95% C.I.)) | Reported Device Performance (Specificity (95% C.I.)) |
|---|---|---|---|---|---|
| Clinical Performance | Chlamydia trachomatis | Clinician-Collected Vaginal Swab (Symptomatic) | High Sensitivity & Specificity | 92.5 (84.4, 97.2) | 98.8 (97.6, 99.5) |
| Self-Collected Vaginal Swab (Symptomatic) | High Sensitivity & Specificity | 94.7 (86.9, 98.5) | 99.0 (97.9, 99.6) | ||
| Female Urine (Symptomatic) | High Sensitivity & Specificity | 92.6 (84.6, 97.2) | 99.5 (98.7, 99.9) | ||
| Female Urine (Asymptomatic) | High Sensitivity & Specificity | 95.7 (85.2, 99.5) | 99.2 (98.2, 99.7) | ||
| Male Urethral Swab (Symptomatic) | High Sensitivity & Specificity | 93.3 (88.6, 96.5) | 98.3 (97.0, 99.1) | ||
| Male Urine (Symptomatic) | High Sensitivity & Specificity | 97.3 (93.7, 99.1) | 99.7 (98.9, 100.0) | ||
| Male Urine (Asymptomatic) | High Sensitivity & Specificity | 97.8 (92.3, 99.7) | 99.6 (98.7, 100.0) | ||
| Neisseria gonorrhoeae | Clinician-Collected Vaginal Swab (Symptomatic) | High Sensitivity & Specificity | 96.8 (83.3, 99.9) | 99.9 (99.2, 100.0) | |
| Self-Collected Vaginal Swab (Symptomatic) | High Sensitivity & Specificity | 96.7 (82.8, 99.9) | 99.7 (98.9, 100.0) | ||
| Female Urine (Symptomatic) | High Sensitivity & Specificity | 93.8 (79.2, 99.2) | 99.7 (99.0, 100.0) | ||
| Female Urine (Asymptomatic) | High Sensitivity & Specificity | 87.0 (66.4, 97.2) | 99.6 (98.7, 99.9) | ||
| Male Urethral Swab (Symptomatic) | High Sensitivity & Specificity | 99.2 (97.0, 99.9) | 99.3 (98.3, 99.8) | ||
| Male Urine (Symptomatic) | High Sensitivity & Specificity | 98.8 (96.4, 99.7) | 99.5 (98.5, 99.9) | ||
| Male Urine (Asymptomatic) | High Sensitivity & Specificity | 100.0 (71.5, 100.0) | 100.0 (99.4, 100.0) | ||
| Analytical Sensitivity | Chlamydia trachomatis | N/A | LOD of 320 copies/assay (95% probability) | 39 copies/assay (95% CI 33-51), confirmed at 320 copies/assay (100% detection) | N/A |
| Neisseria gonorrhoeae | N/A | LOD of 320 copies/assay (95% probability) | 192 copies/assay (95% CI 176-220), confirmed at 320 copies/assay (100% detection) | N/A |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: A total of 3,832 male and female subjects were enrolled in the multi-center clinical study.
- Data Provenance: The data was collected prospectively from subjects at 16 geographically diverse sites in the United States. The sites included physician private practices, public and private STD clinics, and a hospital emergency room.
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 of experts or their qualifications for establishing the ground truth. It states that the ground truth was "determined based on the combined results from the reference assays." While these reference assays are commercially available NAATs and culture, the interpretation or consensus process by human experts is not described.
4. Adjudication Method (for the test set)
The adjudication method used to establish the "patient infected status" (ground truth) was a consensus-based approach using multiple reference assays:
- For females: A subject was categorized as infected for CT or NG if a minimum of two positive results (at least one from each reference NAAT) were reported.
- For males: A subject was categorized as infected for CT or NG if a minimum of two positive results were reported.
- For NG specifically (both sexes): If the reference NG culture assay result was positive, the subject was categorized as infected regardless of NAAT results.
- Not infected status:
- Female: At least one of the reference NAATs reported negative results for all sample types.
- Male: A total of at least two negative results were reported by the reference NAATs.
- Subjects with missing and/or indeterminate results from reference assays were excluded (33 for CT, 35 for NG).
This represents a form of consensus ground truth, leaning towards a "2 out of X positive" rule for infection status, with culture having overriding power for NG.
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
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This device is an in vitro diagnostic (IVD) assay designed for direct, qualitative detection using PCR technology, not an AI-assisted diagnostic tool that would involve human readers interpreting AI output. Therefore, there is no discussion of human reader improvement with or without AI assistance.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, the clinical performance data presented (sensitivity and specificity tables) represents the standalone performance of the Abbott RealTime CT/NG assay (algorithm/device only). The assay itself performs the detection and reporting of qualitative results without a human interpretation loop of the assay's direct output.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The ground truth used was expert consensus based on multiple reference assays, specifically a combination of:
- Two commercially available nucleic acid amplification tests (NAATs) for CT and NG.
- Culture for NG.
8. The Sample Size for the Training Set
The document does not explicitly state a "training set" size for the clinical studies. For IVD assays like this, the development process typically involves internal analytical verification and validation, possibly using characterized samples or spiked samples, but these are generally not referred to as a "training set" in the same way as machine learning models. The reported clinical study of 3,832 subjects serves as the test set for performance evaluation.
9. How the Ground Truth for the Training Set was Established
Since a "training set" in the machine learning sense is not explicitly described or used for this IVD assay according to the provided text, the method for establishing its ground truth for training is not applicable. The device's "training," if interpreted as its development and optimization, would have involved extensive analytical studies (e.g., analytical sensitivity, specificity, interference) using well-characterized samples, which are distinct from the clinical performance evaluation.
§ 866.3120 Chlamydia serological reagents.
(a)
Identification. Chlamydia serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to chlamydia in serum. Additionally, some of these reagents consist of chlamydia antisera conjugated with a fluorescent dye used to identify chlamydia directly from clinical specimens or cultured isolates derived from clinical specimens. The identification aids in the diagnosis of disease caused by bacteria belonging to the genusChlamydia and provides epidemiological information on these diseases. Chlamydia are the causative agents of psittacosis (a form of pneumonia), lymphogranuloma venereum (a venereal disease), and trachoma (a chronic disease of the eye and eyelid).(b)
Classification. Class I (general controls).