(104 days)
The Sierra Diagnostics L.L.C. Urine Collection, Preservation and Transport System is intended for use in the collection, preservation, and transportation of urine specimens at temperatures not exceeding 60°C for testing with the Abbott LCx® Neisseria qonorrhoeae and Chlamydia trachomatis assays.
The device is comprised of a urine collection cup containing of a nucleic acid chemical preservative. The device allows urine specimens for LCx® gonococcal or chlamydial testing to be preserved for up to 6 days at temperatures not to exceed 60°C. Inert indicator beads are included in the urine cup as an indicator that a preservative is present in the sample.
Here's an analysis of the acceptance criteria and study detailed in the provided 510(k) summary:
Given the nature of the device (urine collection, preservation, and transport system) and the provided text, the acceptance criteria are not explicitly stated in numerical terms typical for diagnostic accuracy (e.g., sensitivity, specificity). Instead, the criteria relate to the effectiveness of preservation and correlation of results compared to a predicate method.
1. A table of acceptance criteria and the reported device performance
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Preservation Effectiveness: The device must effectively preserve gonococcal and chlamydial nucleic acid targets in urine specimens, maintaining their integrity for subsequent LCx® testing. | Demonstrated effective preservation of gonococcal and chlamydial nucleic acid targets in urine specimens from symptomatic and asymptomatic males and females. |
| Correlation with Predicate Method: Results from specimens preserved with the Sierra device should correlate with results from specimens preserved via the predicate method (refrigeration). | 100% correlation between refrigerated samples (24 hours) and Sierra-preserved samples (144 hours at 60°C). |
| Preservative Concentration Range & Sensitivity: The device should effectively preserve nucleic acid targets down to the LCx® level of detection across a specified preservative-to-urine ratio. | Effectively preserved nucleic acid targets down to the LCx® level of detection with a preservative to urine ratio ranging from 1:10 to 1:15. |
| Temperature/Time Stability: The device must preserve urine specimens for up to 6 days at temperatures not exceeding 60°C. | LCx® testing compared samples refrigerated for 24 hours with Sierra-preserved samples held for 144 hours (6 days) at 60°C. Implies successful preservation under these conditions. |
2. Sample size used for the test set and the data provenance
- Sample Size:
- Comparative Testing (Spiked Samples): Not explicitly stated how many samples were used for the gonococcal and chlamydial DNA spiking experiment.
- Multi-Site Clinical Study: Not explicitly stated.
- Preservative Concentration Study: Not explicitly stated, but mentioned "urine specimens spiked with less than 10 cfu of 10 different gonococcal serovars." This implies at least 10 specimens, likely more for various concentrations.
- Data Provenance: Not specified (e.g., country of origin). The studies appear to be prospective as they involved controlled experiments (spiking, controlled temperature/time, multi-site clinical study testing the device).
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not applicable. The ground truth for this device is based on laboratory assays (LCx® testing for Neisseria gonorrhoeae and Chlamydia trachomatis nucleic acid detection), not expert consensus on images or clinical findings. The "experts" would be the laboratory technicians performing and interpreting the LCx® assays.
4. Adjudication method for the test set
Not applicable. Ground truth is established by a quantitative laboratory assay (LCx®), not by human interpretation requiring adjudication.
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
Not applicable. This device is a pre-analytic collection, preservation, and transport system, not an AI-assisted diagnostic tool. No human "readers" are involved in interpreting its direct output.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, in essence, the performance shown is standalone for the device's function. The device's ability to preserve nucleic acids is tested directly, and the output (presence/absence of nucleic acid via LCx®) is objective. While the downstream LCx® assay itself is a laboratory test, the performance data presented here focuses solely on the preservation capability of the Sierra device when used with that assay.
7. The type of ground truth used
The ground truth used is primarily laboratory assay results (Abbott LCx® Neisseria gonorrhoeae and Chlamydia trachomatis assays) on fresh or spiked specimens.
- For the comparative testing, the ground truth was the LCx® result of refrigerated fresh samples.
- For the spiking studies, the ground truth was the known presence/absence and concentration of spiked nucleic acid, detected by LCx®.
- For the multi-site clinical study, the ground truth would have been the LCx® results from the freshly collected specimens from symptomatic and asymptomatic individuals, against which the preserved specimens were compared.
8. The sample size for the training set
Not mentioned. This is a medical device for specimen handling, not a machine learning model, so "training set" is not a standard concept here in the sense of model development. The studies described are performance evaluation studies.
9. How the ground truth for the training set was established
Not applicable, as there's no "training set" in the context of machine learning. The studies described are for evaluating the device's performance.
§ 866.2900 Microbiological specimen collection and transport device.
(a)
Identification. A microbiological specimen collection and transport device is a specimen collecting chamber intended for medical purposes to preserve the viability or integrity of microorganisms in specimens during storage of specimens after their collection and during their transport from the collecting area to the laboratory. The device may be labeled or otherwise represented as sterile. The device aids in the diagnosis of disease caused by pathogenic microorganisms.(b)
Classification. Class I (general controls). The device, when solely intended for use in the collection of concentrated parasites from specimens and transport, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 866.9.