MICRO-STRIP FOR MARIJUANA METABOLITES by MICRODIAGNOSTICS, INC.

The MICRO-STRIP FOR MARIJUANA METABOLITES is an immunoassay that qualitatively detects the major Marijuana metabolites (tetrahydrocannabinoids/THC) in urine at the SAMHSA cutoff level of 50 ng/m1. The MICRO-STRIP FOR MARIJUANA METABOLITES is Intended for use by clinical toxicology laboratories, physician offices, drug abuse clinics and law enforcement agencies only.

Device Description

Not Found

AI/ML Overview

This is a 510(k) premarket notification for "MICRO-STRIP FOR MARIJUANA METABOLITES", an immunoassay for qualitatively detecting major marijuana metabolites (tetrahydrocannabinoids/THC) in urine at the SAMHSA cutoff level of 50 ng/ml. The document explicitly states that the device is intended for use by clinical toxicology laboratories, physician offices, drug abuse clinics, and law enforcement agencies. This FDA letter approves the device, meaning it was found substantially equivalent to a predicate device. Often, 510(k) summaries, not the approval letter itself, contain detailed study information. The provided text is an approval letter, not the full submission. Therefore, much of the requested detailed study information is not available in the provided text.

However, based on the nature of the device (an immunoassay detecting a specific metabolite at a cutoff level), we can infer certain aspects of the acceptance criteria and study design, even if the explicit details are missing.

Here's an attempt to answer the questions based on the available information and general knowledge of such devices, highlighting what is directly stated, inferred, or not present.

1. Table of Acceptance Criteria and Reported Device Performance

The provided FDA letter does not include a table of acceptance criteria or specific reported device performance metrics. Such information would typically be found in the 510(k) summary or the full submission, not in the FDA's approval letter.

However, for a qualitative immunoassay like this, the primary performance metrics would likely revolve around:

Sensitivity: The ability of the test to correctly identify samples containing marijuana metabolites at or above the 50 ng/ml cutoff.
Specificity: The ability of the test to correctly identify samples not containing marijuana metabolites above the 50 ng/ml cutoff, or to not react with interfering substances.
Cutoff Performance: Accurate classification of samples around the 50 ng/ml threshold.
Reproducibility/Precision: Consistency of results when tested multiple times.
Cross-reactivity: Assessment against various prescription and over-the-counter drugs, as well as structurally similar compounds, to ensure no false positives.

Inferred Acceptance Criteria (Typical for such devices):

Performance Metric	Acceptance Criteria (Inferred, commonly 95% CI)	Reported Device Performance (Not provided in text)
Sensitivity	≥ 95% Positive Agreement (for samples ≥ 50 ng/ml)	Not provided
Specificity	≥ 97% Negative Agreement (for samples < 50 ng/ml and non-cross-reactive)	Not provided
Cut-off Accuracy	Correct classification for samples near the 50 ng/ml threshold (e.g., ±25%)	Not provided
Reproducibility	Consistent results across multiple runs/operators/lots	Not provided
Cross-reactivity	No significant interference/false positives with common or similar compounds	Not provided

2. Sample size used for the test set and the data provenance

Sample Size for Test Set: Not provided in the given text.
Data Provenance (e.g., country of origin of the data, retrospective or prospective): Not provided in the given text. For clinical toxicology assays, data is often collected from diverse populations, and can be prospective (collecting new samples) or retrospective (using archived samples with known concentrations).

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

Number of Experts: Not applicable/Not provided. For a quantitative chemical analytical method like detecting drug metabolites, the "ground truth" is typically established by a highly sensitive and specific reference method, not by human expert consensus or interpretation.
Qualifications of Experts: Not applicable/Not provided. The "expert" in this context would be the reference laboratory performing the confirmatory testing. This would typically involve highly trained laboratory technicians and chemists using sophisticated analytical instrumentation (e.g., GC/MS or LC/MS/MS).

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

Adjudication Method: Not applicable/None in the traditional sense. As the ground truth is established by an objective reference method, there's no need for human expert adjudication of discrepancies between the device and the ground truth. Discrepancies would be analyzed to understand the assay's performance characteristics.

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

MRMC Study: No. This type of study is relevant for imaging devices or AI-driven diagnostic tools where human interpretation is a key component and AI acts as an assist. The MICRO-STRIP device is a qualitative immunoassay, where the result (e.g., a line appearing or not) is largely objective for the user. It does not involve "readers" in the sense of interpreting complex medical images or data, nor does it involve AI assistance for human interpretation.

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

Standalone Performance: The "MICRO-STRIP FOR MARIJUANA METABOLITES" device is essentially a standalone test. Its performance is evaluated independently against a reference method. It is designed to provide a direct result without a complex human-in-the-loop interpretation or algorithmic intervention beyond the chemical reaction itself. The "human-in-the-loop" component is limited to performing the test correctly and reading the visible result (line or no line).

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

Type of Ground Truth: The ground truth for immunoassay tests like this is almost universally established by a reference analytical method, typically Gas Chromatography-Mass Spectrometry (GC/MS) or Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (LC/MS/MS). These methods are considered the "gold standard" for quantitative confirmation of drug metabolites in biological matrices due to their high specificity and sensitivity. Samples would be tested by the device and then confirmed by GC/MS or LC/MS/MS to determine the true concentration and presence/absence of the metabolite relative to the 50 ng/ml cutoff.

8. The sample size for the training set

Sample Size for Training Set: Not applicable/Not provided. Immunoassays are not "trained" in the machine learning sense. Their performance is inherent in their chemical design (antibodies, reagents). While R&D involves optimizing reagent concentrations and manufacturing processes, there isn't a "training set" of data in the way an AI algorithm uses it. Performance evaluation studies typically use a "test set" or "validation set" of samples.

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

How Ground Truth for Training Set was Established: Not applicable. As explained in question 8, there isn't a "training set" for an immunoassay in the typical sense of establishing ground truth for machine learning. The chemical properties and reactivity of the immunoassay are developed through laboratory experimentation and optimization, not data-driven training.

Summary

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Food and Drug Administration 2098 Gaither Road Rockville MD 20850

AUG - 5 1999

Mr. Roy Chung President Microdiagnostics, Inc. 28062 Forbes Road, Suite B Laguna Niguel, California 92677

Re: K991516

Trade Name: MICRO-STRIP FOR MARIJUANA METABOLITES Regulatory Class: II Product Code: LDJ Dated: July 26, 1999 Received: July 29, 1999

Dear Mr. Chung:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

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Under the Clinical Laboratory Improvement Amendments of 1988 (CLIA-88), this device may require a CLIA complexity categorization. To determine if it does, you should contact the Centers for Disease Control and Prevention (CDC) at (770) 488-7655.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4588. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification"(21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597, or at its internet address "http://www.fda.gov/cdrh/dsma/dsmamain.html".

Sincerely yours.

Steven Sutman

Steven I. Gutman, M.D, M.B.A. Director Division of Clinical Laboratory Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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510 (k) NUMBER (IF KNOWN) :

MICRO-STRIP FOR MARIJUANA METABOLITES DEVICE NAME:

INDICATIONS FOR USE:

Leiva Cooper
(Division Sign-Off)

Division of Clinical Laboratory
510(k) Number K991546

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED.)

Concurrence of CDRH, Office of Device Evaluation i (ODE)

Prescription Use V (Per 21 CFR 801.109) OR

Over - The - Counter - Use (Optional Format 1-2-96)

Regulation Number and Section

§ 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).