(132 days)
Rapid Marijuana (THC) Test Strip 20 and Rapid Marijuana (THC) Test Dipcard 20 is a rapid, screening test for the qualitative detection of Marijuana and their metabolites in human urine at the cut-off concentration of 20 ng/mL.
Rapid Marijuana (THC) Test Strip 50 and Rapid Marijuana (THC) Test Dipcard 50 is a rapid, screening test for the qualitative detection of Marijuana and their metabolites in human urine at the cut-off concentration of 50 ng/mL.
The tests contain two formats:1) Test Strip and 2) Test Dipcard. The tests are intended for in vitro diagnostics use. They are intended for over-the-counter use.
The tests provide only a preliminary result. To obtain a confirmed analytical result, a more specific alternative chemical method must be used. Gas Chromatography/Mass spectrometry (GC/MS) or Liquid chromatography/Mass spectrometry (LC/MS) is the preferred confirmatory method. Clinical consideration and professional judgment should be applied to any drug of abuse test result, particularly when preliminary positive results are obtained.
Rapid Marijuana (THC) Test Strip 20 and Rapid Marijuana (THC) Test Dipcard 20 are competitive binding, lateral flow immunochromatographic assays for qualitatively the detection of Marijuana and their metabolites at or above the cut-off concentration of 20 ng/mL. The tests can be performed without the use of an instrument.
Rapid Marijuana (THC) Test Strip 50 and Rapid Marijuana (THC) Test Dipcard 50 are competitive binding, lateral flow immunochromatographic assays for qualitatively the detection of Marijuana and their metabolites at or above the cut-off concentration of 50 ng/mL. The tests can be performed without the use of an instrument.
Test Strip and Test Dipcard use identical test strips made with same chemical formulation and manufacturing procedures.
This document describes the performance of the Rapid Marijuana (THC) Test Strip and Dipcard devices, available in 20 ng/mL and 50 ng/mL cutoff concentrations, for the qualitative detection of Marijuana and its metabolites in human urine.
Here's an analysis of the provided information:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state pre-defined acceptance criteria in terms of specific performance metrics (e.g., minimum sensitivity, specificity, or agreement percentages for accuracy studies). However, the performance data presented implies a standard of acceptable qualitative detection around the cutoff concentration. The precision and accuracy studies evaluate the device's ability to correctly identify positive and negative samples at various concentrations relative to the cutoff. The home-use study assesses user comprehension and ease of use.
Since no explicit numerical acceptance criteria are provided, I will present key performance indicators from the precision and accuracy studies. For the purpose of this table, I will infer that a high percentage of correct classifications at and around the cutoff, along with 100% correct classification for samples significantly above or below the cutoff, would be considered acceptable.
Inferred Performance Acceptance Criteria & Reported Device Performance for Cut-off 20 ng/mL:
| Performance Metric | Implied Acceptance Criteria (Inferred from data presentation) | Rapid Marijuana (THC) Test Strip 20 Reported Performance (Positive/Negative counts at specified concentrations across 3 lots) | Rapid Marijuana (THC) Test Dipcard 20 Reported Performance (Positive/Negative counts at specified concentrations across 3 lots) |
|---|---|---|---|
| Precision Study | For -75% Cutoff (5 ng/mL): 100% Negative calls or very close | Lot 1: 0 positive, 60 negative | |
| Lot 2: 0 positive, 60 negative | |||
| Lot 3: 0 positive, 60 negative | Lot 1: 0 positive, 60 negative | ||
| Lot 2: 0 positive, 60 negative | |||
| Lot 3: 0 positive, 60 negative | |||
| For -50% Cutoff (10 ng/mL): 100% Negative calls or very close | Lot 1: 0 positive, 60 negative | ||
| Lot 2: 0 positive, 60 negative | |||
| Lot 3: 0 positive, 60 negative | Lot 1: 0 positive, 60 negative | ||
| Lot 2: 0 positive, 60 negative | |||
| Lot 3: 0 positive, 60 negative | |||
| For -25% Cutoff (15 ng/mL): Predominantly Negative calls, some positive possible | Lot 1: 6 positive, 54 negative | ||
| Lot 2: 4 positive, 56 negative | |||
| Lot 3: 4 positive, 56 negative | Lot 1: 4 positive, 56 negative | ||
| Lot 2: 6 positive, 54 negative | |||
| Lot 3: 4 positive, 56 negative | |||
| For Cutoff (20 ng/mL): Mix of Positive and Negative calls (around 50% for each) | Lot 1: 34 positive, 26 negative | ||
| Lot 2: 36 positive, 24 negative | |||
| Lot 3: 32 positive, 28 negative | Lot 1: 36 positive, 24 negative | ||
| Lot 2: 38 positive, 22 negative | |||
| Lot 3: 34 positive, 26 negative | |||
| For +25% Cutoff (25 ng/mL): Predominantly Positive calls, some negative possible | Lot 1: 54 positive, 6 negative | ||
| Lot 2: 56 positive, 4 negative | |||
| Lot 3: 58 positive, 2 negative | Lot 1: 56 positive, 4 negative | ||
| Lot 2: 56 positive, 4 negative | |||
| Lot 3: 58 positive, 2 negative | |||
| For +50% Cutoff (30 ng/mL): 100% Positive calls or very close | Lot 1: 60 positive, 0 negative | ||
| Lot 2: 60 positive, 0 negative | |||
| Lot 3: 60 positive, 0 negative | Lot 1: 60 positive, 0 negative | ||
| Lot 2: 60 positive, 0 negative | |||
| Lot 3: 60 positive, 0 negative | |||
| For +75% Cutoff (35 ng/mL): 100% Positive calls or very close | Lot 1: 60 positive, 0 negative | ||
| Lot 2: 60 positive, 0 negative | |||
| Lot 3: 60 positive, 0 negative | Lot 1: 60 positive, 0 negative | ||
| Lot 2: 60 positive, 0 negative | |||
| Lot 3: 60 positive, 0 negative | |||
| For +100% Cutoff (40 ng/mL): 100% Positive calls or very close | Lot 1: 60 positive, 0 negative | ||
| Lot 2: 60 positive, 0 negative | |||
| Lot 3: 60 positive, 0 negative | Lot 1: 60 positive, 0 negative | ||
| Lot 2: 60 positive, 0 negative | |||
| Lot 3: 60 positive, 0 negative | |||
| Accuracy Study | Overall Agreement: High agreement with LC/MS, especially for samples far from cutoff | Site 1,2,3 (Agreement with LC/MS categories): |
- Neg. (drug free): 27 Negative
- Neg. (+50% cutoff): 31 Positive | Site 1,2,3 (Agreement with LC/MS categories):
- Neg. (drug free): 27 Negative
- Neg. (+50% cutoff): 31 Positive |
| Home Use Consumer Study | Agreement at 0 ng/mL: 100% Negative | 100% Agreement (30 Negative) | 100% Agreement (30 Negative) |
| | Agreement at -50% Cutoff (10 ng/mL): 100% Negative | 100% Agreement (30 Negative) | 100% Agreement (30 Negative) |
| | Agreement at -25% Cutoff (15 ng/mL): High percentage of Negative (e.g.,>90%) | 93% Agreement (2 Positive, 28 Negative) | 90% Agreement (3 Positive, 27 Negative) |
| | Agreement at +25% Cutoff (25 ng/mL): High percentage of Positive (e.g.,>90%) | 90% Agreement (27 Positive, 3 Negative) | 93% Agreement (28 Positive, 2 Negative) |
| | Agreement at +50% Cutoff (30 ng/mL): 100% Positive | 100% Agreement (30 Positive) | 100% Agreement (30 Positive) |
| | Agreement at +100% Cutoff (40 ng/mL): 100% Positive | 100% Agreement (30 Positive) | 100% Agreement (30 Positive) |
Inferred Performance Acceptance Criteria & Reported Device Performance for Cut-off 50 ng/mL:
| Performance Metric | Implied Acceptance Criteria (Inferred from data presentation) | Rapid Marijuana (THC) Test Strip 50 Reported Performance (Positive/Negative counts at specified concentrations across 3 lots) | Rapid Marijuana (THC) Test Dipcard 50 Reported Performance (Positive/Negative counts at specified concentrations across 3 lots) |
|---|---|---|---|
| Precision Study | For -75% Cutoff (12.5 ng/mL): 100% Negative calls or very close | Lots 1,2,3: 0 positive, 60 negative | Lots 1,2,3: 0 positive, 60 negative |
| For -50% Cutoff (25 ng/mL): 100% Negative calls or very close | Lots 1,2,3: 0 positive, 60 negative | Lots 1,2,3: 0 positive, 60 negative | |
| For -25% Cutoff (37.5 ng/mL): Predominantly Negative calls, some positive possible | Lot 1: 4 positive, 56 negative | ||
| Lot 2: 6 positive, 54 negative | |||
| Lot 3: 2 positive, 58 negative | Lot 1: 6 positive, 54 negative | ||
| Lot 2: 2 positive, 58 negative | |||
| Lot 3: 6 positive, 54 negative | |||
| For Cutoff (50 ng/mL): Mix of Positive and Negative calls (around 50% for each) | Lot 1: 36 positive, 24 negative | ||
| Lot 2: 38 positive, 22 negative | |||
| Lot 3: 34 positive, 26 negative | Lot 1: 38 positive, 22 negative | ||
| Lot 2: 34 positive, 26 negative | |||
| Lot 3: 36 positive, 24 negative | |||
| For +25% Cutoff (62.5 ng/mL): Predominantly Positive calls, some negative possible | Lot 1: 56 positive, 4 negative | ||
| Lot 2: 56 positive, 4 negative | |||
| Lot 3: 58 positive, 2 negative | Lot 1: 58 positive, 2 negative | ||
| Lot 2: 56 positive, 4 negative | |||
| Lot 3: 54 positive, 6 negative | |||
| For +50% Cutoff (75 ng/mL): 100% Positive calls or very close | Lots 1,2,3: 60 positive, 0 negative | Lots 1,2,3: 60 positive, 0 negative | |
| For +75% Cutoff (87.5 ng/mL): 100% Positive calls or very close | Lots 1,2,3: 60 positive, 0 negative | Lots 1,2,3: 60 positive, 0 negative | |
| For +100% Cutoff (100 ng/mL): 100% Positive calls or very close | Lots 1,2,3: 60 positive, 0 negative | Lots 1,2,3: 60 positive, 0 negative | |
| Accuracy Study | Overall Agreement: High agreement with LC/MS, especially for samples far from cutoff | Site 1,2,3 (Agreement with LC/MS categories): |
- Neg. (drug free): 21 Negative
- Neg. (+50% cutoff): 30 Positive | Site 1,2,3 (Agreement with LC/MS categories):
- Neg. (drug free): 21 Negative
- Neg. (+50% cutoff): 30 Positive |
| Home Use Consumer Study | Agreement at 0 ng/mL: 100% Negative | 100% Agreement (30 Negative) | 100% Agreement (30 Negative) |
| | Agreement at -50% Cutoff (25 ng/mL): 100% Negative | 100% Agreement (30 Negative) | 100% Agreement (30 Negative) |
| | Agreement at -25% Cutoff (37.5 ng/mL): High percentage of Negative (e.g.,>90%) | 97% Agreement (1 Positive, 29 Negative) | 93% Agreement (2 Positive, 28 Negative) |
| | Agreement at +25% Cutoff (62.5 ng/mL): High percentage of Positive (e.g.,>90%) | 93% Agreement (28 Positive, 2 Negative) | 93% Agreement (28 Positive, 2 Negative) |
| | Agreement at +50% Cutoff (75 ng/mL): 100% Positive | 100% Agreement (30 Positive) | 100% Agreement (30 Positive) |
| | Agreement at +100% Cutoff (100 ng/mL): 100% Positive | 100% Agreement (30 Positive) | 100% Agreement (30 Positive) |
2. Sample Size Used for the Test Set and the Data Provenance
- Precision Study:
- Sample Size: For each device type (Strip 20, Dipcard 20, Strip 50, Dipcard 50), 3 lots were tested. Each lot involved 60 determinations for each of 9 concentration levels, across 6 operators at 3 Point-of-Care sites over 10 non-consecutive days. This totals to 1620 observations per device type in the precision study.
- Data Provenance: The document does not explicitly state the country of origin for the urine samples. The study involved spiking drug-free urine specimens. The study itself was conducted at 3 Point-of-Care sites, but their locations are not specified. It is a prospective study as samples were prepared and tested specifically for this evaluation.
- Accuracy Study:
- Sample Size: 80 clinical urine specimens were used for each device type (Strip 20, Dipcard 20, Strip 50, Dipcard 50) and each operator site. Since there were 3 operator sites, this amounts to 80 * 3 = 240 tests (device results vs. LC/MS) for each specificity (20 ng/mL and 50 ng/mL).
- Data Provenance: The samples were described as "clinical urine specimens," implying they were collected from human subjects. The country of origin is not specified, and it's unclear if they were retrospective or prospectively collected for the study.
- Home Use Consumer Study:
- Sample Size: 180 lay users participated in the study. Each user performed 1 test on a provided specimen. The samples were prepared for the study. For each device type and concentration category, 30 determinations were made.
- Data Provenance: The document does not specify the country of origin of the lay users or the urine samples used. It is a prospective study.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts
- Precision Study: The ground truth for the spiked samples was established by the precise concentration of "-)-11-nor-9-Carboxy-Δ⁹-THC" added to drug-free urine, confirmed with LC/MS. No human experts were involved in establishing this ground truth, as it was based on laboratory preparation and analytical confirmation.
- Accuracy Study: The ground truth for the clinical urine specimens was established by LC/MS (Gas Chromatography/Mass spectrometry or Liquid chromatography/Mass spectrometry). LC/MS is described as the "preferred confirmatory method." LC/MS is an analytical chemistry technique, not a human expert. Therefore, no human experts directly established the ground truth in this study; it was based on objective analytical measurement.
- Home Use Consumer Study: Similar to the precision study, the ground truth for samples was established by spiking drugs into urine with concentrations confirmed by LC/MS. No human experts were involved in establishing this ground truth.
4. Adjudication Method for the Test Set
- Precision Study: The results were read by operators comparing the test line intensity to the control line. There is no mention of an adjudication process for discrepancies in reading within the precision study; each determination (positive/negative) was recorded independently.
- Accuracy Study: The device results were compared directly to the LC/MS results. Discordant results are noted in tables (e.g., device positive when LC/MS was negative below cutoff, or device negative when LC/MS was positive above cutoff), but no formal adjudication method (like 2+1 reading) is described beyond this direct comparison.
- Home Use Consumer Study: The "Layer user Results" likely represent the interpretation of the test by the lay users themselves. No specific adjudication method is mentioned.
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
There was no MRMC comparative effectiveness study done. The device is a rapid, screening immunoassay test (similar to a pregnancy test) for qualitative detection of THC metabolites in urine, designed for Over-The-Counter use. It is interpreted visually by the user or an operator. There is no AI component in this device, nor is there a comparison of human readers with vs. without AI assistance.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
This is not applicable as the device is a lateral flow immunochromatographic assay requiring human visual interpretation. It is not an algorithm-only device. The results are read visually.
7. The Type of Ground Truth Used
- Cross-reactivity and Interference Studies: Ground truth was established by precisely preparing samples with known concentrations of various compounds and expected drug-free or drug-spiked urine.
- Precision Study: Ground truth for the concentration levels of (-)-11-nor-9-Carboxy-Δ⁹-THC was confirmed using LC/MS.
- Accuracy Study: Ground truth for clinical urine specimens was established by LC/MS (Gas Chromatography/Mass spectrometry or Liquid chromatography/Mass spectrometry).
- Home Use Consumer Study: Ground truth for the spiked samples was confirmed using LC/MS.
In summary, the primary ground truth method for quantitative confirmation of drug concentrations in samples was LC/MS.
8. The Sample Size for the Training Set
This information is not applicable to this device. As a rapid, screening immunoassay test, it does not involve machine learning or AI models that require a "training set." Its performance is based on the chemical reactions and visual detection inherent in the lateral flow assay.
9. How the Ground Truth for the Training Set Was Established
This is not applicable as there is no training set for this device type.
§ 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).