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For In Vitro Diagnostic Use.

The Immunalysis SEFRIA Methamphetamine Oral Fluid Enzyme Immunoassay is an enzyme immunoassay with a cutoff of 50 ng/mL in neat oral fluid collected by Quantisal II Oral Fluid Collection Device. The assay is intended for the qualitative and semi-quantitative analysis of methamphetamine in human oral fluid with clinical analyzers. This assay is calibrated against d-methamphetamine.

The semi-quantitative mode is for purposes of enabling laboratories to determine an appropriate dilution of the specimen for confirmation by a confirmatory method such as Gas Chromatography/Mass Spectrometry (GC-MS) or Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS) or permitting laboratories to establish quality control procedures.

The Immunalysis SEFRIA Methamphetamine Oral Fluid Enzyme Immunoassay provides only a preliminary analytical test result. A more specific alternate chemical must be used in order 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. Clinical consideration and professional judgment should be applied to any test result, particularly when preliminary positive results are used.

The Immunalysis SEFRIA Methamphetamine Oral Fluid Enzyme Immunoassay is an in-vitro test to detect the presence of methamphetamine in human oral fluid samples collected by Quantisal or Quantisal II Oral Fluid Collection Device.

The provided document describes the performance characteristics of the Immunalysis SEFRIA Methamphetamine Oral Fluid Enzyme Immunoassay for the detection of methamphetamine in human oral fluid. This is a medical device, and the data presented supports its substantial equivalence to a legally marketed predicate device (LZI Oral Fluid Methamphetamine Enzyme Immunoassay [K131652]).

The document details various studies, primarily focusing on analytical performance rather than diagnostic accuracy involving human subjects. Therefore, many of the typical acceptance criteria and study aspects for AI-powered diagnostic devices (e.g., expert consensus for ground truth, MRMC studies, human-in-the-loop performance) are not applicable here. This device performs a chemical analysis.

Here's an analysis based on the provided text, addressing the relevant points:

Acceptance Criteria and Reported Device Performance

The acceptance criteria for this type of in-vitro diagnostic device are generally defined by demonstrating analytical performance metrics such as precision, specificity, linearity, and stability, with results falling within acceptable ranges. Substantial equivalence is often shown by comparing these metrics to a predicate device.

1. Table of Acceptance Criteria and Reported Device Performance:

Since this is an in-vitro diagnostic device, the "acceptance criteria" are implied by the expected performance common for such assays, aiming for high agreement with confirmed methods and consistent results. The document states a design goal of ">95% agreement" for method comparison.

• 0-37.5 ng/mL: 100% Negative (60/60)
• 50 ng/mL (Cutoff): 26 Neg/34 Pos
• 62.5-100 ng/mL: 100% Positive (60/60)
  Quantisal II Pad A:
• 0-37.5 ng/mL: 100% Negative (60/60)
• 50 ng/mL (Cutoff): 34 Neg/26 Pos
• 62.5-100 ng/mL: 100% Positive (60/60)
  Quantisal II Pad B:
• 0-37.5 ng/mL: 100% Negative (60/60)
• 50 ng/mL (Cutoff): 31 Neg/29 Pos
• 62.5-100 ng/mL: 100% Positive (60/60) |
  | Precision (Semi-Quantitative) | Mean concentration values close to expected spiked concentrations, and consistent classification. | Quantisal: Mean concentrations generally close to spiked values (e.g., 50 ng/mL mean 50.2 ng/mL). Classification performance similar to qualitative.
  Quantisal II Pad A: Mean concentrations generally close to spiked values (e.g., 50 ng/mL mean 48.6 ng/mL). Classification performance similar to qualitative.
  Quantisal II Pad B: Mean concentrations generally close to spiked values (e.g., 50 ng/mL mean 49.0 ng/mL). Classification performance similar to qualitative. |
  | Specificity/Cross-Reactivity | Minimal to no cross-reactivity with structurally unrelated compounds; expected cross-reactivity with structurally similar compounds. | - Structurally Similar: Varies. High cross-reactivity with MDMA (90.9%), (±)-3,4-Methylenedioxyethylamphetamine (45.5%), PMMA (180.2%), and some with d,l-Methamphetamine (45.5%), l-Ephedrine (1.2%), Fenfluramine (1.0%), MDA (0.8%), Methylone (0.2%), PMA (1.5%), d-Pseudoephedrine (0.3%), l-Pseudoephedrine (0.1%), d-Amphetamine (0.6%), l-Methamphetamine (0.7%).
• Structurally Unrelated: No interference observed at tested high concentrations (Table 9 shows a wide range of compounds tested up to 40,000 ng/mL). |
  | Interference (Endogenous/Exogenous) | No interference from common endogenous or exogenous substances. | No interference observed for a wide range of endogenous (e.g., Albumin, Bilirubin, Hemoglobin, Salivary-alpha-amylase) and exogenous (e.g., Acetylsalicylic Acid, Caffeine, Alcohol, Mouthwash, Toothpaste) compounds at tested levels. |
  | Interference (pH) | Performance maintained across physiological pH range. | No interference observed across pH 3.0-11.0. |
  | Linearity/Recovery | Recovery percentage within an acceptable range (e.g., 90-110%) across the linear range. | Linear range confirmed for 20-200 ng/mL. Recovery percentages: Quantisal (93.9-107.9%), Quantisal II "A" (96.8-104.0%), Quantisal II "B" (96.2-109.2%). |
  | Methamphetamine Stability | Stability of analyte in collected samples over time under specified storage conditions. | Oral fluid samples stable for up to 12 months at 2°C - 8°C. Data for 10-day stability at ambient temperature (8°C - 25°C) referenced in previous submissions (K183048, K200801). |
  | Calibration Duration | Consistent performance over defined calibration interval. | Achieved acceptance criteria up to 10 days. Recommended frequency: 7 days. |
  | Method Comparison (Qualitative & Semi-Quantitative) | Agreement with confirmatory method (LC-MS/MS) greater than 95%. | Achieved 100% agreement (40/40) for both positive and negative results when compared to LC-MS/MS across all three collection devices (Quantisal, Quantisal II "A", Quantisal II "B"). The total samples tested were 80, partitioned into 40 positive and 40 negative categories by LC-MS/MS. |

2. Sample Size and Data Provenance:

• Precision Study: 60 determinations for each concentration level, replicating across 15 days, 2 runs/day, 2 collection devices/run (N=60 per conc.). An additional 20-day study on 3 reagent lots for repeatability.
  • Provenance: Not explicitly stated (e.g., country of origin). The study states "Drug free negative oral fluid was spiked," implying a controlled laboratory setting (prospective creation of samples).
• Specificity and Cross-Reactivity: Compounds spiked into drug-free pooled oral fluid.
  • Provenance: Controlled laboratory (prospective creation of samples).
• Interference (Structurally Unrelated): Compounds spiked into drug-free oral fluid containing methamphetamine at ±25% of cutoff.
  • Provenance: Controlled laboratory (prospective creation of samples).
• Interference (Endogenous/Exogenous): Spiking into drug-free oral fluid; "Additional orally used products were tested by collecting oral fluid... from volunteers after use of the substances."
  • Provenance: Mix of controlled laboratory (prospective creation) and possibly prospective volunteer studies.
• Interference (pH): Spiked samples at various pH levels.
  • Provenance: Controlled laboratory (prospective creation of samples).
• Linearity/Recovery: Serially diluted spiked samples.
  • Provenance: Controlled laboratory (prospective creation of samples).
• Methamphetamine Stability: Spiked samples stored over time.
  • Provenance: Controlled laboratory (prospective creation of samples).
• Calibration Duration: Spiked samples tested over time.
  • Provenance: Controlled laboratory (prospective creation of samples).
• Method Comparison: 80 deidentified, unaltered clinical oral fluid samples collected by Quantisal II Oral Fluid Collection Devices.
  • Provenance: "Obtained from clinical research facilities," suggesting real-world clinical samples, likely retrospective. Country of origin not specified.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

This is an in-vitro diagnostic (IVD) device for chemical analysis, not an imaging AI or clinical decision support system that relies on human expert interpretation of complex clinical data. Therefore, the concept of "experts" establishing ground truth in the traditional sense (e.g., radiologists, pathologists) is not directly applicable.

For the analytical studies performed, the "ground truth" is established very precisely through:

• Spiking concentrations: Known amounts of methamphetamine or other compounds are added to drug-free oral fluid. The exact concentration is the ground truth.
• LC-MS/MS (Liquid Chromatography-Tandem Mass Spectrometry): This is a highly accurate and widely accepted gold-standard method for confirming drug presence and concentration in biological samples. The results from LC-MS/MS served as the "ground truth" for the method comparison study. The laboratory performing this analysis would follow strict protocols and be staffed by trained analytical chemists or toxicologists, but no "expert consensus" process among multiple human interpreters is involved as it would be for an image-based diagnosis.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:

Not applicable. Ground truth for an IVD drug test is established by precise chemical methods (spiking, LC-MS/MS), not through subjective human interpretation requiring 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:

Not applicable. This is an automated enzyme immunoassay (chemical test), not an AI-powered diagnostic assist tool for human readers/interpreters. There are no human "readers" in the loop.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

The device (assay performed on a clinical analyzer) functions as a standalone test. Its performance is reported solely based on its analytical output against the chemically defined ground truth (spiked concentrations, LC-MS/MS).

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

The ground truth was established through:

• Known Spiked Concentrations: For precision, specificity, interference, linearity, stability, and calibration studies.
• Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS): For the method comparison study, LC-MS/MS results served as the definitive ground truth for "deidentified, unaltered clinical oral fluid samples".

8. The sample size for the training set:

Not applicable. This device is an enzyme immunoassay, a biochemical assay, not a machine learning/AI model that requires a "training set" in the computational sense. Its "training" is inherent in the chemical reactions and calibration curves established by the manufacturer, validated through the performance studies described.

9. How the ground truth for the training set was established:

Not applicable, as there is no "training set" in the context of an AI/ML algorithm. The assay's analytical characteristics are determined through standard laboratory validation practices using materials with known characteristics (e.g., calibrated standards, spiked samples).

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