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"Rapid Drug Screen" with methamphetamine is a one-step , lateral flow immunoassay for the simulatenous detection in urine of five abused drugs at stated detectable limits. (Each assay occupies a seperate channel). It is intended for use in the qualitative detection of d-Amphetamine (750 ng/ml), Benzoyl ecgonine (225 ng/ml), Cannabinoids (50 ng/ml), Methamphetamines (1000 ng/ml) and Opiates (225 ng/ml).

"Rapid Drug Screen" is intended for use by professional laboratories. The assays are easy to perform, but should not be used without proper supervision. These immunoassay is a simplified qualatative screening method that provides only a preliminary result for use in the need for aditional or confirmatory testing, i.e., gas-chromatography/mass spectrometry (GC/MS).

"Rapid Drug" screen provides only a preliminary analytical test result. A more specific alternate chemical method must be used to obtain a more confirmed analytical result. Gas chromatography/mass spectrometry (GC/MS) is the preferred confirmatory method. Clinical and professional judgement should be applied to any drug of abuse test result, particulary when preliminary positive results are used.

All of the assays employed in the Rapid Drug Screen panels are based on the same principle of highly specific reaction between antigens and antibodies.

Each assay is a one-step, immunoassay in which a specially labeled drug (drug conjugate) competes with drug which may be present in the sample for the limited number of binding sites on the antibody. The test device consists of a membrane strip onto which a drug conjugate has been immobilized. A colloidal gold-antibody complex is dried at one end of the membrane. In the absence of any drug in the urine sample, the colloidal gold-antibody complex moves with the urine by capillary action to contact the immobilized drug conjugate. An antibody-antigen reaction occurs forming a visible line in the "test" area. The formation of a visible line in the test area occurs when the test is below the cut-off for the drug.

When drug is present in the urine sample, the drug or metabolite will compete with the immobilized drug conjugate in the test area for the limited antibody sites on the colloidal gold-labeled antibody complex.. If sufficient amount of drug is present, it will fill all of the available binding sites, thus preventing attachment of the labeled antibody to the drug conjugate. An absence of a color band (line) in the test area is indicative of a positive result.

A control band (line), comprised of a different antibody/antigen reaction, is present on the membrane strip. The control line is not influenced by the presence or absence of drug in the urine, and therefore, should be present in all reactions.

A negative urine will produce two colored bands, and a possitive sample will produce only one band.

Here's an analysis of the provided 510(k) summary regarding the acceptance criteria and the study that proves the device meets them:

Device: Rapid Drug Screen 5-Panel with Methamphetamine

1. Table of Acceptance Criteria and Reported Device Performance

Note: The acceptance criteria are implicitly defined by the cut-off levels at which the device is intended to detect the drugs. The reported performance refers to the agreement with established comparator methods.

2. Sample Size Used for the Test Set and Data Provenance

• d-Amphetamine:
  • 75 negative specimens
  • 40 positive specimens
  • Total: 115
• Benzoyl ecgonine (cocaine):
  • 75 negative specimens
  • 40 positive specimens
  • Total: 115
• Cannabinoids (THC):
  • 75 negative specimens
  • 40 positive specimens
  • Total: 115
• Opiates:
  • 75 negative specimens
  • 40 positive specimens
  • Total: 115
• Methamphetamines:
  • Total: 454 specimens
    • 256 below cut-off (negative)
    • 198 positive (by EMIT II)
• Data Provenance: The data used clinical specimens. The country of origin is not specified but implicitly assumed to be the US given the submission to the FDA. The study appears to be retrospective, as it uses "clinical specimens" that were subsequently analyzed.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications

The summary does not specify the number or qualifications of experts. However, the ground truth was established by laboratory methods, not expert consensus.

4. Adjudication Method for the Test Set

Adjudication by human experts is not applicable here. The ground truth for the test set was established using reference laboratory methods:

• Primary Comparator for d-Amphetamine, Benzoyl ecgonine, Cannabinoids, and Opiates: Syva EMIT II for initial positive/negative determination.
• Primary Comparator for Methamphetamines: Syva EMIT II.
• Confirmatory Method for all drugs: Gas Chromatography/Mass Spectrometry (GC/MS) was used to verify concentrations for both positive and negative samples, as well as discordant samples.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done

No, an MRMC comparative effectiveness study was not done. This device is an in-vitro diagnostic test for qualitative detection of substances in urine, not an imaging device or a device requiring human interpretation for its primary output. Therefore, improvement of human readers with or without AI assistance is not relevant to this type of device.

6. If a Standalone Study (algorithm only without human-in-the-loop performance) was done

Yes, the studies described are standalone performance evaluations. The device's output (presence or absence of a line) is directly compared against established laboratory reference methods (EMIT II, GC/MS). There is no human interpretation integrated into the device's performance assessment itself. The intended use states it provides a "preliminary result" for use in determining the need for additional or confirmatory testing, implying it's a standalone screening tool.

7. The Type of Ground Truth Used

The ground truth used was a combination of:

• Reference Immunoassay: Syva EMIT II for initial positive/negative classification.
• Confirmatory Analytical Method: Gas Chromatography/Mass Spectrometry (GC/MS) was used to verify actual drug concentrations in both positive and negative samples, and importantly, to analyze discordant results. This is considered a highly reliable and definitive method for drug quantification.

8. The Sample Size for the Training Set

The summary does not provide information on a training set. For immunoassay devices like this, the development process typically involves optimizing antibody-antigen reactions and conjugation during R&D, rather than "training" an algorithm in the way a machine learning model is trained. The data presented here is for analytical performance validation/testing.

9. How the Ground Truth for the Training Set Was Established

As no training set is described, the method for establishing its ground truth is not applicable. The development of such diagnostic devices involves extensive laboratory testing and optimization of reagents and cut-off points, but not in the sense of a data-driven "ground truth establishment" for a training set in machine learning.

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