(143 days)
The Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) is a visually read lateral flow immunoassay test intended for the qualitative detection of SARS-CoV-2 virus nucleocapsid protein antigen directly in anterior nasal swab specimens from individuals with signs and symptoms of COVID-19.
This test is for non-prescription home use by individuals aged 14 years or older testing themselves, or adults testing individuals aged 2 years or older.
All negative results are presumptive. Symptomatic individuals with an initial negative test result must be re-tested once between 48 and 72 hours after the first test using either an antigen test or a molecular test for SARS-CoV-2. Negative results do not rule out SARS-CoV-2 infections or other pathogens and should not be used as the sole basis for treatment. Positive results do not rule out co-infection with other respiratory pathogens.
This test is not a substitute for visits to a healthcare provider or appropriate follow-up and should not be used to determine any treatments without provider supervision. Individuals who test negative and experience continued or worsening COVID-19 like symptoms, such as fever, cough and/or shortness of breath, should seek follow up care from their healthcare provider.
The performance characteristics for SARS-CoV-2 were established from April, 2023 to February, 2024 when SARS-CoV-2 Omicron was dominant. Test accuracy may change as new SARS-CoV-2 viruses emerge. Additional testing with a lab-based molecular test (e.g., PCR) should be considered in situations where a new virus or variant is suspected.
The Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) is a lateral flow immunoassay intended for non-prescription home use qualitative detection of nucleocapsid protein antigen directly in anterior nasal swab specimens from individuals with signs and symptoms of COVID-19 within the first five (5) days of symptom onset. Results are for the identification of SARS-CoV-2 nucleocapsid protein antigen. The test cassette in the test kit is assembled with a test strip in a plastic housing that contains a nitrocellulose membrane with two lines: a test line (T line) and a control line (C line).
The device is for in vitro diagnostic use only.
The Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) consists of the following components:
- . Tube Holder (located in kit box)
- Test Cassette ●
- Tube (pre-filled extraction buffer) ●
- Swab ●
- Quick Reference Instructions ●
The provided 510(k) summary for the Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) describes the acceptance criteria and a clinical study demonstrating the device's performance.
Here's a breakdown of the requested information:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for home-use COVID-19 antigen tests often involve minimum Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA) compared to a highly sensitive molecular comparator. While the document doesn't explicitly state "acceptance criteria" as a separate section with specific thresholds, the clinical performance results can be interpreted against expected standards for such devices. For the purpose of this response, we'll assume the achieved performance in the clinical study is what the manufacturer and FDA found acceptable for market clearance.
| Metric (for symptomatic individuals within 5 days of symptom onset) | Acceptance Criteria (Implied by clearance and industry standards for OTC Antigen tests) | Reported Device Performance |
|---|---|---|
| Positive Percent Agreement (PPA) | Generally expected to be above a certain threshold (e.g., >80-85%) | 84.38% (95% CI: 77.10% - 89.65%) |
| Negative Percent Agreement (NPA) | Generally expected to be very high (e.g., >98-99.5%) | 99.67% (95% CI: 99.03% - 99.89%) |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: 1032 evaluable subjects within 5 days of symptom onset (from a total of 1053 enrolled subjects).
- Data Provenance: Prospective clinical study conducted between April 2023 and February 2024 at nine (9) clinical sites. The country of origin is not explicitly stated, but the manufacturer is Guangzhou Wondfo Biotech Co., Ltd. in China, and the study was likely conducted with data collected in alignment with international regulatory standards for medical device submissions.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document states that the ground truth was established using an "FDA-cleared highly sensitive molecular comparator method." This implies that the ground truth was derived from the result of a molecular test, not directly by a panel of human experts reviewing the cases. Therefore, information on the number and qualifications of experts for ground truth establishment for the clinical test set is not applicable in this context, as the comparator method serves as the ground truth.
4. Adjudication Method for the Test Set
The document does not describe an explicit adjudication method for the test set results. The comparison is made between the Wondfo 2019-nCoV Antigen Test and an "FDA-cleared highly sensitive molecular comparator method." It is implied that the results of the molecular comparator method are taken as the definitive ground truth without further 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
This section is not applicable as the Wondfo 2019-nCoV Antigen Test is a visually read lateral flow immunoassay intended for non-prescription home use. It is not an AI-assisted diagnostic device, nor is it designed for interpretation by multiple expert readers in an MRMC study setting. The device is a standalone test read by lay users.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
Yes, a standalone performance study was conducted. The clinical study described in section 6 and the non-clinical performance studies (sections 5.1-5.5) represent the standalone performance of the test as it would be used by a lay user without "human-in-the-loop" expert interpretation beyond the visual reading of the test lines by the user.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
The ground truth for the clinical study was established by an FDA-cleared highly sensitive molecular comparator method (e.g., PCR), which is considered the gold standard for SARS-CoV-2 detection.
8. The Sample Size for the Training Set
The document does not explicitly mention a "training set" in the context of machine learning or AI. This device is a lateral flow immunoassay, a biochemical test, not an AI/ML-based diagnostic. Therefore, the concept of a training set for an algorithm is not applicable. The device's manufacturing and design would have involved internal validation and optimization, but not in the sense of an algorithm training on a dataset.
9. How the Ground Truth for the Training Set was Established
As explained in point 8, the concept of a training set and its ground truth in the AI/ML sense is not applicable to this lateral flow immunoassay device. The device's performance is based on its biochemical reactions and physical design, which are validated through non-clinical and clinical studies.
N/A