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The DRI Cocaine Metabolite Assay is a homogeneous enzyme immunoassay intended for the qualitative and/or semi- quantitative determination of benzoylecgonine (Cocaine Metabolite) in human urine at a cutoff concentration of either 150 ng/mL or 300 ng/mL.

The semi-quantitative mode is for the purpose of enabling laboratories to determine an appropriate dilution of the specimen for confirmation by a confirmatory method such as Liquid Chromatography/tandem mass spectrometry (LC- MS/MS) or permitting laboratories to establish quality control procedures.

The assay provides only a preliminary analytical test result. A more specific alternative chemical method must be used to obtain a confirmed analytical result. Gas chromatography / Mass spectrometry (GC/MS) or Liquid chromatography/ tandem mass spectrometry (LC-MS/MS) is the preferred confirmatory method. Tests for cocaine metabolite cannot distinguish between abused drugs and certain prescribed medications.

Clinical and professional judgment should be applied to any drug of abuse test result, particularly when preliminary results are used. For In Vitro Diagnostic Use Only.

The DRI Cocaine Metabolite Assay is a homogeneous enzyme immunoassay using ready-to-use liquid reagents. The assay uses a specific antibody, which can detect benzoylecgonine in urine. The assay is based on the competition of an enzyme glucose-6-phosphate dehydrogenase (G6PDH) labeled drug and the drug from the urine sample for a fixed amount of specific antibody binding sites. In the presence of free drug from the sample, the free drug occupies the antibody binding sites, allowing the drug-labeled G6PDH to interact with the substrate, resulting in enzyme activity. In the absence of drug from the sample, the specific antibody binds to the drug labeled with G6PDH and the enzyme activity is inhibited. This phenomenon creates a direct relationship between the drug concentration in the urine and the enzyme activity. The enzyme G6PDH activity is determined spectrophotometrically at 340 mm by measuring its ability to convert nicotinamide adenine dinucleotide (NAD) to NADH.

The assay consists of reagents (A and E).

Reagent A: Contains mouse monoclonal anti-benzoylecgonine antibody, glucose-6-phosphate (G6P), and nicotinamide adenine dinucleotide (NAD) in Tris buffer with sodium azide as preservative.

Reagent E: Contains benzoylecgonine analog labeled with glucose-6-phosphate dehydrogenase (G6PDH) in HEPES buffer with sodium azide as preservative.

The DRI Cocaine Metabolite Assay is a homogeneous enzyme immunoassay intended for the qualitative and/or semi-quantitative determination of benzoylecgonine (Cocaine Metabolite) in human urine at cutoff concentrations of either 150 ng/mL or 300 ng/mL. The study performed aims to demonstrate the analytical performance of the device and its substantial equivalence to the predicate device, Cocaine Metabolite Enzyme Immunoassay (K960187).

Here's an analysis of the acceptance criteria and study details:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state pre-defined acceptance criteria values for agreement percentages (e.g., "must be >95%"). However, the reported performance demonstrates 100% agreement with the reference method (LC-MS/MS) for both positive and negative samples at both cutoff levels in the method comparison study. The precision studies also show consistent determination of positive and negative results at concentrations significantly above and below the cutoff, with expected mixed results at the cutoff itself.

2. Sample Size for the Test Set and Data Provenance

• Precision Studies:
  • For both qualitative and semi-quantitative modes and both cutoffs (150 ng/mL and 300 ng/mL): 80 replicates (2 replicates per day for 20 days).
  • Includes samples with Benzoylecgonine spiked at cutoff, 25%, 50%, 75%, and 100% above and below the cutoff.
• Spike Recovery: 21 replicates for each spiked concentration (112.5 ng/mL and 187.5 ng/mL for 150 ng/mL cutoff; 225 ng/mL and 375 ng/mL for 300 ng/mL cutoff).
• Analytical Recovery and Linearity: 9 intermediate levels (plus 0 and 1025 ng/mL), each run in replicates of five.
• Method Comparison and Accuracy:
  • 100 patient samples were analyzed.
• Specificity (Cocaine metabolites): Not specified by number of samples, but by "known amounts of each compound."
• Specificity (Structurally Unrelated Compounds): Not specified by number of samples, but by spiking into low and high control urine.
• Interference (Physiologic Substances & pH): Not specified by number of samples, but by spiking into low and high control urine.
• Specific Gravity Interference: Not specified by number of samples, but by spiking drug-free urine with varying specific gravities.

Data Provenance: The studies were performed at the manufacturer's site (Microgenics Corporation, Thermo Fisher Scientific). The data appears to be retrospective (spiked samples, patient samples compared to LC-MS/MS). The country of origin of the data is not explicitly stated, but the manufacturer is based in Fremont, California, USA.

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

This being an in vitro diagnostic (IVD) device for drug toxicology, the ground truth is established by a reference analytical method rather than human expert interpretation of images or clinical findings.

• No human experts were used to establish ground truth for the test set.
• The primary reference method for accuracy studies was LC-MS/MS (Liquid Chromatography/tandem Mass Spectrometry), which is considered the preferred confirmatory method for drug testing due to its high specificity and sensitivity.

4. Adjudication Method

As ground truth was established by an objective analytical method (LC-MS/MS) and not human reader consensus, no adjudication method (e.g., 2+1, 3+1) was applicable or used.

5. Multi Reader Multi Case (MRMC) Comparative Effectiveness Study

No MRMC study was conducted or is applicable for this type of IVD device. This device is an immunoassay for determining drug metabolites, not an AI-powered diagnostic imaging tool that assists human readers. Therefore, the concept of human reader improvement with AI assistance is not relevant here.

6. Standalone Performance Study

Yes, a standalone performance study was done. The entire document describes the performance of the algorithm/device only (DRI Cocaine Metabolite Assay) without human-in-the-loop performance, against established analytical standards and a reference method (LC-MS/MS). The device generates a preliminary analytical test result independently.

7. Type of Ground Truth Used

The ground truth used for performance evaluation, particularly for accuracy and method comparison, was Liquid Chromatography/tandem Mass Spectrometry (LC-MS/MS). This is a highly accurate chemical method considered the gold standard for confirming drug presence and concentration. For precision, spike recovery, and interference studies, the ground truth involved precisely spiking known concentrations of the analyte into drug-free urine.

8. Sample Size for the Training Set

The document describes the analytical performance of a finished device. It does not mention any "training set" in the context of machine learning. This device is a biochemical immunoassay, not a machine learning model that requires a training set.

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

As mentioned above, there is no disclosed "training set" or machine learning component in the context of this immunoassay. Therefore, this question is not applicable.

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