(14 days)
The Redi-Screen is a qualitative, one step, immunochromatographic competitive assay for the qualitative determination of the presence of THC, Phencyclidine, Opiates, Cocaine and Methamphetamine at the following cut off concentrations;
| THC | 50ng/mL |
|---|---|
| PCP | 25ng/mL |
| Opiates | 300ng/mL |
| Cocaine | 300ng/mL |
| Methamphetamine | 1,000ng/mL |
The test is qualitative and provides only a preliminary analytical result, which must be confirmed by an alternate methodology preferably, GC/MS.
This test is for use in clinical laboratories by health care and forensic professionals only.
The Redi-Screen is an immunochromatographic based one step in vitro test.
Here's an analysis of the provided text, focusing on the acceptance criteria and study information for the Redi-Screen device:
It's important to note that the provided text is a 510(k) Summary and an FDA clearance letter, which typically do not contain detailed clinical study reports. Therefore, much of the requested information (like sample sizes for test sets, expert qualifications, adjudication methods, multi-reader studies, and training set details) is not present in this document. The focus here is on demonstrating substantial equivalence to a predicate device based primarily on analytical performance, not extensive human-in-the-loop clinical assessments.
Acceptance Criteria and Reported Device Performance
The core "acceptance criteria" for this device are established by its functionality as a qualitative screening test for specific drugs of abuse (DOA) at defined cut-off levels. The "reported device performance" is essentially that it achieves these cut-off levels and is substantially equivalent to existing individual tests.
Table of Acceptance Criteria and Reported Device Performance:
| Drug of Abuse (DOA) | Acceptance Criterion (Cut-off Level) | Reported Device Performance (Achieves Cut-off) |
|---|---|---|
| THC | 50 ng/mL | Yes, as stated in substantial equivalence |
| PCP | 25 ng/mL | Yes, as stated in substantial equivalence |
| Opiates | 300 ng/mL | Yes, as stated in substantial equivalence |
| Cocaine | 300 ng/mL | Yes, as stated in substantial equivalence |
| Methamphetamine | 1,000 ng/mL | Yes, as stated in substantial equivalence |
Summary of Study to Prove Device Meets Acceptance Criteria:
The study proving the device meets its acceptance criteria is framed as a Substantial Equivalence comparison to five existing, legally marketed predicate devices (Redi-THC, Redi-PCP, Redi-Cocaine, Redi-Opiates, and Redi-Methamphetamine).
The document states:
"The Redi-Screen was found substantially equivalent to the five single tests for the individual DOA. i.e., the Redi-THC. Redi-PCP. Redi-Cocaine. Redi-Opiates and Redi-Methamphetamine. All products are immunoassays and use specific antibodies to detect various drug compounds. Both predicate and modified tests are preliminary screens for human urine and require confirmation with alternate methods such as GC/MS. The sensitivity for the Redi Screen is equivalent to the single tests."
This indicates that the Redi-Screen's ability to detect the specified drugs at or above the cut-off levels was deemed equivalent to the established performance of the predicate devices. This equivalence implies that the Redi-Screen effectively meets the analytical performance "acceptance criteria" defined by these cut-off levels, consistent with other similar immunoassay screening tests.
Detailed Information (Based on available text):
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Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective):
- Not specified in the provided text. The document focuses on the type of comparison (substantial equivalence) rather than the detailed methodology and sample sizes of the underlying analytical studies. Urine specimens are mentioned, but no specifics on quantity or origin.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience):
- Not applicable/Not specified. For an in-vitro diagnostic (IVD) immunoassay like this, "ground truth" is typically established by objective analytical methods (e.g., GC/MS or comparison to known standards/controls) rather than expert consensus on images or clinical cases. The document mentions "clinical laboratories by health care and forensic professionals," but this refers to the users of the test, not experts establishing ground truth for a study.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not applicable/Not specified. Adjudication methods like 2+1 or 3+1 are typically used in imaging studies where there's human interpretation involved and potential for disagreement. This is an IVD device, where the output is a qualitative (positive/negative) result based on a chemical reaction.
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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. This is an in-vitro diagnostic device, not an AI-assisted diagnostic imaging or clinical decision support tool. MRMC studies are not relevant here.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, in essence. The Redi-Screen is a standalone immunoassay device. Its performance is evaluated based on its ability to detect the target substances in a sample, independent of human interpretation beyond reading the visual bands. While a human reads the result, the "performance" described (detection at cut-off) is of the device itself.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- The "ground truth" for this type of device is typically established by confirmed analytical methods, most commonly Gas Chromatography/Mass Spectrometry (GC/MS). The intended use statement explicitly supports this: "The test is qualitative and provides only a preliminary analytical result, which must be confirmed by an alternate methodology preferably, GC/MS." This implies that GC/MS would be the gold standard for confirming the presence and concentration of the drugs.
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The sample size for the training set:
- Not applicable/Not specified. This is an immunoassay, not a machine learning model that requires a "training set" in the conventional sense. The "training" for such devices involves assay development, optimization, and characterization studies, not data-driven model training.
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How the ground truth for the training set was established:
- Not applicable/Not specified. As there's no machine learning training set, this question is not relevant. The "ground truth" for developing and validating the assay's performance would be derived from known-concentration controls and samples confirmed by reference methods like GC/MS.
§ 862.3610 Methamphetamine test system.
(a)
Identification. A methamphetamine test system is a device intended to measure methamphetamine, a central nervous system stimulating drug, in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of methamphetamine use or overdose.(b)
Classification. Class II (special controls). A methamphetamine test system is not exempt if it is intended for any use other than employment or insurance testing or is intended for Federal drug testing programs. The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9, provided the test system is intended for employment and insurance testing and includes a statement in the labeling that the device is intended solely for use in employment and insurance testing, and does not include devices intended for Federal drug testing programs (e.g., programs run by the Substance Abuse and Mental Health Services Administration (SAMHSA), the Department of Transportation (DOT), and the U.S. military).