(272 days)
The Nano-Check™ COVID-19 Antigen Test is a lateral flow immunochromatographic assay for the rapid, qualitative detection of SARS-CoV-2 nucleoprotein antigens directly in anterior nasal swab specimens from individuals with signs and symptoms of upper respiratory infection (i.e., symptomatic) when testing is started within 4 days of symptom onset. The test is intended for use as an aid in the diagnosis of SARS-CoV-2 infections (COVID-19) in symptomatic individuals when either: tested at least twice over three days with at least 48 hours between tests; or when tested once, and negative by the Nano-Check™ COVID-19 Antigen Test and followed up with a molecular test.
The test does not differentiate between SARS-CoV or SARS-CoV-2.
A negative test result is presumptive, and it is recommended these results be confirmed by a molecular SARS-CoV-2 assay. Positive results do not rule out co-infection with other bacteria or viruses and should not be used as the sole basis for diagnosis, treatment, or other patient management decisions.
Performance characteristics for SARS-CoV-2 were established during the 2022-2023 SARS-CoV-2 pandemic when SARS-CoV-2 Omicron was the predominant SARS-CoV-2 variant in circulation. When other SARS-CoV-2 virus variants are emerging, performance characteristics may vary.
The Nano-Check™ COVID-19 Antigen Test is an immunochromatographic assay for detection of extracted SARS-CoV-2 nucleoprotein antigens in human anterior nasal swab specimens.
The assay kit consists of 20 test cassette devices, 20 reagent tubes containing extraction buffer for Set A or 20 empty reagent tubes and 20 ampules containing extraction buffer for Set B, 20 anterior nasal specimen collection swabs, one positive control swab, one negative control swab and an Instructions for Use/Quick Reference Instruction. An external positive control swab is used with recombinant SARS-CoV-2 nucleocapsid dried onto the swab and an external negative control swab contains blank universal viral transport media dried on the swab. The kit should be stored at 2°C - 30°C.
Here's an analysis of the acceptance criteria and the study that proves the Nano-Check COVID-19 Antigen Test meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for clinical performance are implicitly derived from the reported Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA). While explicit numerical acceptance targets are not stated, the device's performance is presented in comparison to a molecular RT-PCR test.
| Metric | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Positive Percent Agreement (PPA) | Acceptable level for aiding in diagnosis of SARS-CoV-2 infections in symptomatic individuals | 83.67% (95% CI: 76.86-88.78%) |
| Negative Percent Agreement (NPA) | Acceptable level for ruling out SARS-CoV-2 infections, with a recommendation for molecular confirmation | 99.62% (95% CI: 98.62-99.90%) |
For analytical performance, acceptance criteria are generally "no interference" for cross-reactivity and endogenous/exogenous interference, and "100% agreement" for precision and reproducibility at moderate to high concentrations.
| Metric (Analytical) | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Repeatability (MP & TN samples) | 100% agreement | 100% agreement |
| Repeatability (LP & HN samples) | >95% agreement | >95% agreement (95.8% for LP, 96.9% for HN) |
| Reproducibility (All samples across sites) | No significant difference in performance between sites | All samples tested generated no significant difference |
| Cross-Reactivity/Microbial Interference | No cross-reactivity/interference | "No" for all 43 microorganisms/substances tested |
| Endogenous/Exogenous Interference | No interference with positive or negative results | "No" for all 20 substances tested |
| Biotin Interference | No interference up to the concentration tested | No interference up to 3,500 ng/mL |
| External Controls Lot-to-Lot Reproducibility | 100% agreement with expected results | 100% agreement for all lots |
| Specimen Stability (2x LoD positive samples) | Stable for recommended storage duration | Stable up to 24 hours at room temperature, 48 hours at 2°C-8°C |
| Limit of Detection (LoD) | Established LoD for relevant variants | 1.95x10^2 TCID50/mL for Omicron (e.g.) |
| Analytical Reactivity (Inclusivity) | 100% detection at a certain viral concentration | 100% detection (5/5) at listed LoD for 15 SARS-CoV-2 isolates/variants |
| High Dose Hook Effect | No Hook Effect | 100% positive results across tested high concentrations |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size (Clinical Study Test Set): 670 subjects
- Data Provenance: Multi-center, prospective clinical study in the U.S. in 2022-2023. At the time of the study, the SARS-CoV-2 Omicron variant was the predominant strain.
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 or qualifications of experts used to establish the ground truth for the clinical study. The ground truth was established using an "FDA Cleared SARS-CoV-2 RT-PCR Test as comparator." RT-PCR tests are molecular diagnostic methods and are considered the gold standard for SARS-CoV-2 detection, generally not requiring expert interpretation for generating positive/negative results.
4. Adjudication Method for the Test Set
The document does not explicitly state an adjudication method (like 2+1, 3+1, none) for discordant results between the Nano-Check COVID-19 Antigen Test and the RT-PCR comparator. The results are presented directly from this comparison.
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
There was no MRMC comparative effectiveness study and no mention of AI or human readers being assisted by AI in this context. This device is a visually-read, lateral flow immunochromatographic assay, meaning results are interpreted directly by the user looking at control and test lines.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
This is not applicable as the device is a visually-read assay. There is no algorithm for standalone performance. The interpretation is directly by the user.
7. The Type of Ground Truth Used (Expert Consensus, Pathology, Outcomes Data, etc.)
The ground truth used for the clinical study was an FDA Cleared SARS-CoV-2 RT-PCR Test. This is considered the molecular "gold standard" for detecting the presence of SARS-CoV-2 viral RNA.
8. The Sample Size for the Training Set
The document does not report a sample size for a training set. This is expected as the Nano-Check COVID-19 Antigen Test is a traditional immunoassay, not an AI/machine learning-based device that typically requires a training set. The "training" of such a device is in its biochemical formulation and physical design, not in data-driven algorithm optimization.
9. How the Ground Truth for the Training Set was Established
As no training set is mentioned or applicable for this type of device, this information is not provided.
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