(386 days)
Output the intended / indications for use exactly as it appears in the overview without any additional commentary or backticks:
The OHC COVID-19 Antigen Self Test is a visually read lateral flow immunoassay device intended for the rapid, qualitative detection of SARS-CoV-2 nucleocapsid protein antigens 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 and 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 infection with SARS-CoV-2 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 June 2023 to July 2023 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 when a new virus or variant is suspected.
The OHC COVID-19 Antigen Self Test is a lateral flow chromatographic immunoassay intended to detect the nucleocapsid protein antigen from SARS-CoV-2 in non-prescription home use from:
- Self-collected anterior nasal (nares) swab specimens from individuals aged 14 years and older with symptoms of COVID-19 within the first 6 days of symptom onset.
- Adult-collected anterior nasal (nares) swab specimens from individuals aged 2 years and older with symptoms of COVID-19 within the first 6 days of symptom onset.
The OHC COVID-19 Antigen Self Test is based on a lateral flow immunoassay and detects the N-Protein (nucleocapsid protein) of SARS-CoV-2. The cassette contains membranes which are pre-coated with anti-SARS-CoV-2 nucleocapsid protein monoclonal antibodies on test line. Another anti-SARS-CoV-2 nucleocapsid protein monoclonal antibodies are bound to colloidal gold. When the sample is loaded to the sample inlet, SARS-CoV-2 antibodies, that were conjugated with the small colloidal gold articles, and SARS-CoV-2 antigen complexes are formed and travel up the strip. If the sample contains SARS-CoV-2 antigens ("analyte"), the complexes will be captured by coated antibodies on membrane to form an analyte-labeled antibody complex. When these complexes reach the test line of the cassette they are retained by another set of SARS-CoV-2 antibodies. This so-called sandwich complex appears as a visible pink/purple line on the test line (T). The presence of SARS- CoV-2 antigen will be indicated by a visible red test line in T-marked (T) position on side of result window. If the sample does not contain SARS-CoV-2 antigens, no sandwich complexes are formed and thus no colored line appears on the test line (T). Regardless of the presence or absence of SARS-CoV-2 antigens in the sample, a colored line will appear on the control line (C). The control (C) line appears in each result window when sample has flowed through the strip. The control line is used as an internal procedural control. The control line should always appear if the test procedure is performed properly and the reagents are working as intended. If no colored line appears on the control line (C), it implies that the test has not worked as intended.
Here's a breakdown of the acceptance criteria and study details for the OHC COVID-19 Antigen Self Test, based on the provided FDA 510(k) clearance letter:
Acceptance Criteria and Device Performance
The provided document does not explicitly state "acceptance criteria" numerical targets in the same way one might find in a design specification. Instead, it describes the results of the performance studies which the FDA presumably found acceptable for clearance. The "performance characteristics for SARS-CoV-2 were established" and the device demonstrates "substantial equivalence" to the predicate. For the purpose of this response, the PPA and NPA values from the clinical study are considered the primary performance metrics for acceptance.
Table 1: Acceptance Criteria (Implied) and Reported Device Performance
| Criterion Description (Implied Acceptance) | Reported Device Performance |
|---|---|
| Clinical Performance (Symptomatic Individuals) | |
| Positive Percent Agreement (PPA) | 85.3% (95% CI: 78.1%-90.4%) |
| Negative Percent Agreement (NPA) | 99.3% (95% CI: 98.2%-99.7%) |
| Analytical Sensitivity (Limit of Detection - LoD) | |
| LoD for heat-inactivated SARS-CoV-2 (USA/MD-HP20874/2021) | 2.51 x 10³ TCID₅₀/mL |
| LoD for International Standard for SARS-CoV-2 antigen (NIBSC code: 21/368) | 1,000 IU/mL (50 IU/swab) |
| Inclusivity / Analytical Reactivity | Reactivity shown for multiple SARS-CoV-2 variants at stated concentrations (e.g., Omicron (BA.2.3) at 5.85 x 10² TCID₅₀/mL) |
| Cross-Reactivity / Microbial Interference | No cross-reactivity or interference observed for most tested substances except SARS-coronavirus (rAg) at 1 µg/mL (resolved with titration to 0.001 µg/mL) |
| Interfering Substances | None of 25 tested substances interfered at specified concentrations (exception for Mupirocin at 10mg/mL leading to false negatives in presence of SARS-CoV-2, but resolved at 5mg/mL) |
| Hook Effect | No Hook Effect observed up to 5.01 x 10⁵ TCID₅₀/mL |
| Precision (Lot-to-Lot and Operator Variability) | 100% agreement for negative and moderate positive (4xLoD) samples across 3 lots and 2 readers in Study 1; 69.4% to 72.2% for low positive (0.75xLoD) samples in Study 2 (still considered acceptable for a low-positive threshold) |
| Flex Studies (Robustness) | Assay demonstrated robustness to various use-related errors |
Study Details
The provided document describes both analytical and clinical studies.
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Sample size used for the test set and the data provenance:
- Clinical Study Test Set: 709 evaluable subjects.
- Data Provenance: Prospective clinical study conducted at four (4) sites in the United States. Samples were collected by lay users (self-collected or adult-collected for household members). Data was collected from June 2023 to July 2023 when SARS-CoV-2 Omicron was dominant.
- Analytical Sensitivity (LoD) Study:
- Preliminary LoD: 5 replicates per dilution, tested on 3 lots.
- Confirmatory LoD: 20 replicates for the confirmed LoD concentration (and other concentrations), for each of 3 kit lots.
- Inclusivity Study: 5 replicates per dilution for each of 9 SARS-CoV-2 strains/isolates.
- Wet Testing JN.1: 5 replicates per dilution.
- Cross Reactivity/Microbial Interference Study: 3 replicates for each organism/virus in the absence and presence of SARS-CoV-2.
- Interfering Substances Study: 3 replicates for each substance in the presence and absence of SARS-CoV-2.
- Hook Effect Study: 5 swabs tested.
- Precision Study (Study 1): 60 replicates per lot (3 lots), for 3 sample types (negative, 1xLoD, 4xLoD), across 2 operators (360 total tests per operator, per sample type).
- Precision Study (Study 2): 72 total tests per sample level (0.75xLoD, 4xLoD, negative). This was 3 lots x 2 operators x 3 days x 2 runs x 2 replicates.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document implies the ground truth for the clinical study was established by a "highly sensitivity molecular FDA 510(k) cleared SARS-CoV-2 assay." This suggests a lab-based molecular test (likely PCR) was used, which is generally performed and interpreted by trained laboratory professionals. The specific number and qualifications of experts interpreting these molecular tests or acting as adjudicators for the overall study are not detailed in the provided text.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- The document does not explicitly describe an adjudication method for the clinical test set. The comparison is made directly against the "highly sensitivity molecular FDA 510(k) cleared SARS-CoV-2 assay."
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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, an MRMC comparative effectiveness study involving AI assistance for human readers was not done. This device is a "visually read lateral flow immunoassay device" for "non-prescription home use by individuals aged 14 years and older testing themselves, or adults testing individuals aged 2 years or older." It does not incorporate AI or involve human readers in the traditional sense of medical image interpretation. The "readers" mentioned in the precision studies refer to individuals interpreting the test strip results, not specialists like radiologists or pathologists.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, in the sense that the device itself is a standalone test. The performance metrics (PPA, NPA) directly represent the OHC COVID-19 Antigen Self Test's ability to detect SARS-CoV-2 antigens based on visual interpretation of the test strip, without any human-in-the-loop involvement beyond following the instructions for use and reading the result. There is no "algorithm" separate from the biochemical reaction that produces a visual line.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- For the clinical evaluation, the primary ground truth was a "highly sensitivity molecular FDA 510(k) cleared SARS-CoV-2 assay" (likely PCR), which is a widely accepted laboratory standard for SARS-CoV-2 detection.
- For analytical studies (LoD, inclusivity, cross-reactivity, hook effect), the ground truth was established using known concentrations of heat-inactivated SARS-CoV-2 virus or other microorganisms/substances.
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The sample size for the training set:
- The provided document describes performance studies (analytical and clinical) for the device. It does not mention a training set in the context of machine learning or AI models, as this is a lateral flow immunoassay, not an AI-powered diagnostic. The mentioned studies are primarily verification and validation studies to demonstrate the device's performance characteristics.
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How the ground truth for the training set was established:
- As no training set for an AI/ML model is described, this question is not applicable. The device's design and manufacturing processes are validated through the analytical and clinical studies presented.
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