(28 days)
FaStep Marijuana Tests are immunochromatographic assays for the qualitative determination of 11-nor-A9-THC-9-COOH in human urine at a cut-off concentration of 50ng/mL. The test is available in a Strip format, a Panel Dip format, a Quick Cup format and a Turn-Key Split Cup format. The test provides only preliminary test results. A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. GC/MS is the preferred confirmatory method. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary result is positive. For in vitro diagnostic use only. It is intended for over-the-counter and for prescription use.
FaStep Methamphetamine Tests are immunochromatographic assays for the qualitative determination of methamphetamine in human urine at a cut-off concentration of 1000 ng/mL. The test is available in a Strip format, a Panel Dip format, a Quick Cup format and a Turn-Key Split Cup format. The test provides only preliminary test results. A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. GC/MS is the preferred confirmatory method. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary result is positive. For in vitro diagnostic use only. It is intended for over-the-counter and for prescription use.
Immunochromatographic assays for Marijuana and Methamphetamine Urine Tests use a lateral flow system for the qualitative detection of 11-nor-A9-THC-9-COOH and Methamphetamine (target analyte) in human urine. Each assay uses a monoclonal antibody-dye conjugate against drugs with gold chloride and fixed drug-protein conjugates and anti-mouse IgG polyclonal antibody in membranes.
This document describes the performance characteristics of the FaStep Marijuana Tests and FaStep Methamphetamine Tests. These are immunochromatographic assays for the qualitative determination of 11-nor-Δ9-THC-9-COOH (Marijuana metabolite) and Methamphetamine in human urine, manufactured by POLYMED THERAPEUTICS, INC. The document presents data to demonstrate that the devices meet acceptance criteria for precision, cut-off verification, interference, specificity, and comparison with a reference method (GC/MS).
Here's a breakdown of the requested information, adapted from the provided text:
1. Acceptance Criteria and Reported Device Performance
The acceptance criteria are implied by the performance of the device in various studies. The core acceptance is accurate qualitative determination (positive/negative) at specific cut-off concentrations, with high correct result percentages and low rates of false positives/negatives, especially near the cut-off.
Overall Performance Summary (Inferred Acceptance Criteria vs. Reported Performance):
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Precision | Accurate classification (positive/negative) for samples at various concentrations relative to the cut-off (especially near the cut-off), with minimal misclassifications. | For both THC and MET tests across all formats (Strip, Panel Dip, Quick Cup, Turn-Key Split Cup), samples at -100%, -75%, -50%, -25% cut-off consistently showed 50-/0+ results (Negative), indicating 100% agreement with expected negative results. Samples at +25%, +50%, +75%, +100% cut-off uniformly showed 50+/0- results (Positive), indicating 100% agreement with expected positive results. At the exact cut-off concentration, there were a small number of misclassifications (e.g., 1-3 negative results out of 50 tests for expected positive, or 1-3 positive results for expected negative, depending on the lot), demonstrating high accuracy at the analytical threshold. |
| Cut-off Verification | All samples at and above +25% cut-off should be positive; all samples at and below -25% cut-off should be negative. | All Marijuana and Methamphetamine tests reported "all positive at and above +25% cut-off and all negative at and below -25% cut-off" when tested with three different lots by three different operators. This demonstrates accurate performance with respect to the defined cut-off values (50 ng/mL for THC, 1000 ng/mL for MET). |
| Interference | No interference from common physiological/pathological substances or specified compounds that would alter the test result. | A wide range of compounds (over 80 for THC, over 90 for MET) at 100 µg/mL concentration showed no interference with test results in both drug-free urine and urine spiked with drugs at +/- 25% of the cut-off. "No differences observed for different formats." |
| Specificity (Cross-Reactivity) | Low cross-reactivity with structurally similar compounds or metabolites, ensuring the test primarily detects the target analyte. Specificity thresholds are not explicitly stated, but the results demonstrate a controlled level of cross-reactivity where expected (e.g., metabolites). | THC: 11-nor-Δ8-THC-9-COOH and (-)-11-nor-9-carboxy-Δ9-THC showed high cross-reactivity (167%) as expected for similar metabolites. Other related compounds (e.g., Δ8-Tetrahydrocannabinol, Cannabinol) showed very low cross-reactivity (0.05% - 0.3%). |
MET: 3,4-Methylenedioxymethamphetamine (MDMA) showed high cross-reactivity (200%), which is physiologically relevant for methamphetamine testing. Other compounds showed lower cross-reactivity (e.g., L-Methamphetamine at 10%, Ephedrine at 25%) or were not detected (D-Amphetamine). "No differences observed for different formats." |
| Comparison Studies (Clinical Samples) | High agreement with GC/MS results, particularly for samples near the cut-off, demonstrating clinical validity. Minimal discordant results. | For both THC and MET tests across all formats, 80 clinical samples (40 negative, 40 positive) were tested. The tables show a high concordance with GC/MS results. Discordant results primarily occurred for samples very close to the cut-off concentration, either false positives slightly below cut-off or false negatives slightly above cut-off (e.g., 1-2 discordant results per viewer for THC and MET strip format, typically within 25% of the cut-off). Overall high agreement was demonstrated. |
| Lay-User Study | High percentage of correct interpretations by lay users, and clear, easy-to-understand instructions. | Across all formats (Strip, Panel Dip, Turn-Key Split Cup, Quick Cup) for both THC and MET, lay users achieved 100% correct results for samples at -100%, -75%, -50% cut-off (negative) and +25%, +50%, +75% cut-off (positive). For samples at -25% cut-off, correct results ranged from 90.2% to 95.2% (some false positives). For samples at +25% cut-off, THC tests showed 100% correct results, while MET tests showed 95.2% to 100% depending on the format. All lay users indicated that the device instructions were easily followed (Flesch-Kincaid Grade Level 7). |
2. Sample Size and Data Provenance
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Precision Studies:
- Sample Size: For each drug (THC, MET), each concentration level (-100%, -75%, -50%, -25%, cut-off, +25%, +50%, +75%, +100% cut-off), across 3 different lots of the device, 50 tests were performed (2 runs per day for 25 days). This means for each drug and each format, 9 concentrations x 3 lots x 50 tests = 1350 data points per format were generated for precision, although only summarized frequency counts are provided.
- Data Provenance: Not explicitly stated, but implied to be laboratory-controlled samples prepared by spiking drugs into negative samples. The concentration was confirmed by GC/MS. This suggests a retrospective controlled laboratory study, likely conducted in the US (given the FDA submission).
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Cut-off Verification:
- Sample Size: 150 samples equally distributed at concentrations of -50% cut-off, -25% cut-off, cut-off, +25% cut-off, +50% cut-off. These were tested using three different lots of each device.
- Data Provenance: Laboratory-controlled spiked samples.
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Interference & Specificity:
- Sample Size: Concentrations of various compounds were tested in drug-free urine and in urine containing target drugs at 25% below and 25% above the cut-off. Tested using three batches (lots) of each device for all formats.
- Data Provenance: Laboratory-controlled spiked samples.
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Comparison Studies (Clinical Samples):
- Sample Size: 80 unaltered clinical samples per drug (40 negative and 40 positive, categorized based on GC/MS). These samples were used for each of the four device formats (Strip, Panel Dip, Quick Cup, Turn-Key Split Cup).
- Data Provenance: "In-house with three laboratory assistants." Samples were "unaltered clinical samples." The country of origin is not specified but is implicitly the US for an FDA submission. This was a retrospective study using existing clinical samples.
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Lay-User Study:
- Sample Size: 147 lay persons. Urine samples were prepared at 7 concentration levels (negative, +/- 75%, +/- 50%, +/- 25% of the cut-off). Each participant was provided with 1 blind-labeled sample (implying each individual participant tested one sample concentration per drug type and format, making the overall sample count for analysis 21 samples per concentration level per drug type - 7 concentrations x 21 participants = 147 tests. Since both THC and MET were tested per participant per format, this would be 147 x 2 = 294 tests per format (or total if formats were varied).
- Data Provenance: "Performed at three intended user sites." Controlled spiked samples, blind-labeled. This was a prospective study with lay users.
3. Number of Experts and Qualifications for Ground Truth
- Expert Establishment of Ground Truth: The ground truth for all analytical and clinical comparison studies was established by GC/MS (Gas Chromatography/Mass Spectrometry). This is a highly accurate and widely accepted "gold standard" method for confirming drug concentrations in urine.
- Qualifications of Experts: The document does not specify the number or detailed qualifications of the individuals who performed the GC/MS analysis (e.g., "radiologist with 10 years of experience"). However, GC/MS is a laboratory analytical method, and it is assumed that the personnel operating such sophisticated equipment are qualified laboratory technicians/scientists with appropriate training and experience in analytical chemistry. For the comparison studies, three laboratory assistants performed the device readings. Their specific qualifications beyond "laboratory assistants" are not detailed.
4. Adjudication Method for the Test Set
- No formal adjudication method (e.g., 2+1, 3+1) is explicitly described for the individual readings of the rapid tests in the comparison studies.
- For the comparison studies, three laboratory assistants ("Viewers A, B, C") independently read the results of the 80 clinical samples for each device format. Their individual readings were then compared against the GC/MS ground truth. The discordant results are individually listed for each viewer against the GC/MS result. This implies independent assessment rather than a consensus or adjudication process among the viewers themselves for the final study result.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No Multi-Reader Multi-Case (MRMC) comparative effectiveness study was done regarding human readers improving with AI vs. without AI assistance.
- This device is a rapid diagnostic test (lateral flow immunoassay) for drug screening, not an "AI-assisted" diagnostic imaging device (e.g., for radiology). Therefore, the concept of "human readers improve with AI vs. without AI assistance" is not applicable here.
- The "human readers" in the comparison studies were laboratory assistants reading the strip/panel for a visible line, and lay users following instructions. There is no AI component involved in the interpretation of these tests according to the documentation provided.
6. Standalone (Algorithm Only) Performance
- Not applicable. As stated above, this is a chemical immunoassay, not an algorithm-only device. The test itself performs the "detection" by the presence or absence of a colored line, which is then interpreted by a human user. There is no software algorithm that provides a standalone diagnostic output without human involvement.
7. Type of Ground Truth Used
- The primary and definitive ground truth for all analytical and comparison studies was GC/MS (Gas Chromatography/Mass Spectrometry) results. GC/MS is a highly precise and accurate analytical method used to identify and quantify substances, making it a robust form of outcomes data or a highly regarded reference standard for determining the true concentration of drug metabolites in urine.
8. Sample Size for the Training Set
- Not applicable. This device is a biochemical immunoassay, not an AI/machine learning model that requires a "training set" of data. The manufacturing process and reagent formulations are established through traditional laboratory development and quality control, not through data-driven model training.
9. How Ground Truth for the Training Set Was Established
- Not applicable. As there is no training set for an AI/machine learning model, there is no ground truth to be established for such a set. The "ground truth" (i.e., known concentrations of analytes) used in the analytical performance studies (precision, cut-off, interference, specificity) was established by carefully prepared spiked samples with concentrations confirmed by GC/MS.
§ 862.3870 Cannabinoid test system.
(a)
Identification. A cannabinoid test system is a device intended to measure any of the cannabinoids, hallucinogenic compounds endogenous to marihuana, in serum, plasma, saliva, and urine. Cannabinoid compounds includedelta -9-tetrahydrocannabinol, cannabidiol, cannabinol, and cannabichromene. Measurements obtained by this device are used in the diagnosis and treatment of cannabinoid use or abuse and in monitoring levels of cannabinoids during clinical investigational use.(b)
Classification. Class II (special controls). A cannabinoid 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).