(157 days)
Instant-View Marijuana (THC) Urine Test (Cassette) is a qualitative one step lateral flow, competitive binding immunoassay device intended to be used to detect 11-nor-delta-9, THC-carboxylic acid (THC), a major metabolites of marijuana in human urine at a cutoff level of 50 ng/ml. It is intended for health care professional use only.
The test provides only a preliminary analytical test result. A more specific alternate chemical method must be used in order to obtain a confirmed analytical result. Gas Chromatography/Mass Spectrophotometry (GC/MS) is the preferred confirmatory method. Clinical consideration and professional judgment should be applied to any drug of abuse, particularly when preliminary positive results are used.
This test is a one-step lateral flow chromatographic immunoassay.
Here's an analysis of the provided text regarding the Alfa Scientific Designs, Inc. Instant-View™ Marijuana (THC) Urine Cassette Test, structured to address your specific questions:
The provided text focuses on the 510(k) submission for a diagnostic device. It describes the device, its intended use, and claims substantial equivalence to a predicate device based on performance characteristics.
Acceptance Criteria and Device Performance Summary
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Correlation with Predicate Device | "higher than 96.7 %" (Implied minimum for substantial equivalence to predicate) | "higher than 96.7 %" |
| Overall Agreement (Accuracy) | "greater than 96.4 %" (Implied minimum for substantial equivalence) | "greater than 96.4 %" (based on clinical laboratory and P.O.L. evaluation) |
Note: The document implies the "acceptance criteria" through statements of achievement for substantial equivalence. Explicit criteria values are not provided as a separate list but rather as the achieved performance which was deemed acceptable.
Study Details
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The document does not explicitly state the total number of samples used in the accuracy evaluation. It mentions "results of the accuracy evaluation from the clinical laboratory & three physician's office laboratory," suggesting multiple sites contributed data, but the specific number of cases tested is not provided.
- Data Provenance: The document does not specify the country of origin of the data. It indicates the data came from a "clinical laboratory" and "three physician's office laboratory," suggesting a prospective clinical evaluation, but it doesn't explicitly state "retrospective" or "prospective." Given that accuracy was evaluated, it's highly likely to be prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The concept of "experts" and "ground truth" in the context of identifying THC in urine typically refers to a reference method, not individual human interpreters for diagnostic readings.
- The ground truth in this case is established by the predicate device (QuikStrip One Step Marijuana Test, manufactured by Syntron Bioresearch, Inc.) and a more specific alternate chemical method for confirmation.
- The document explicitly states: "A more specific alternate chemical method must be used in order to obtain a confirmed analytical result. Gas Chromatography/Mass Spectrophotometry (GC/MS) is the preferred confirmatory method."
- Therefore, the "experts" are the analytical instruments and validated methodologies of a clinical laboratory, not human readers assessing images or clinical findings.
4. Adjudication Method for the Test Set
Not applicable in this context. Adjudication methods like 2+1 or 3+1 typically apply to studies where multiple human readers independently interpret results and discrepancies need to be resolved. For a qualitative, competitive binding immunoassay like this, the "reading" is typically objective (presence/absence of a line) and compared against a reference method (GC/MS or the predicate device). Discrepancies would involve retesting or review by laboratory personnel following standard operating procedures, rather than an "adjudication committee."
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 device is a standalone in-vitro diagnostic assay for detecting a substance in urine, not an AI-assisted diagnostic imaging or interpretation tool that involves human readers in the primary diagnostic step.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
Yes, in essence, a "standalone" performance evaluation was conducted. The device itself (the cassette test) produces a result (presence or absence of a line) which is then interpreted by a healthcare professional. The performance metrics (correlation and agreement) are for the device's ability to accurately detect THC compared to a reference standard, independent of human interpretive variability beyond simply reading the lines according to instructions. The device essentially is the "algorithm" in this context.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The primary ground truth described for confirmation is Gas Chromatography/Mass Spectrophotometry (GC/MS), which is an analytical gold standard for substance identification and quantification. For the broader comparison, the predicate device's results served as a comparative ground truth.
8. The Sample Size for the Training Set
Not applicable. This is an immunoassay device, not a machine learning or AI model that requires a "training set." Its performance is based on the chemical and biological interactions built into the test strip.
9. How the Ground Truth for the Training Set was Established
Not applicable, as there is no "training set" for this type of device.
§ 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).