(210 days)
IMMULITE® Cannabinoids is a solid-phase, chemiluminescent enzyme immunoassay designed for use with the IMMULITE" Automated Analyzer for the semiquantitative and qualitative measurement for cannabinoids and metabolites in urine. It is intended strictly for in vitro diagnostic use in the context of a program involving an established confirmatory test for tetrahvdrocannabinol (THC. cannabis, marijuana) and its metabolites
IMMULITE® Cannabinoids is a solid-phase, chemiluminescent enzyme immunoassay designed for use with the IMMULITE" Automated Analyzer for the semiquantitative and qualitative measurement for cannabinoids and metabolites in urine. It is intended strictly for in vitro diagnostic use in the context of a program involving an established confirmatory test for tetrahvdrocannabinol (THC. cannabis, marijuana) and its metabolites.
IMMULITE® Cannabinoids is a solid-phase. chemiluminescent immunoassay. The solid phase, a polystyrene bead enclosed within an IMMULITE® Test Unit, is coated with a monoclonal antibody specific for cannabinoids. The patient sample and alkaline phosphatase-conjugated 11-nor-A -tetrahvdrocannabinol-9-carboxylic acid (THCA) are simultaneously introduced into the Test Unit, and incubated for 30 minutes at 37°C with intermittent agitation. During this time, cannabinoids in the sample compete with the enzyme-labeled THC for a limited number of antibody binding sites on the bead. Unbound enzyme conjugate is then removed by a centrifugal wash, after which substrate is added and the Test Unit is incubated for a further 10 minutes.
The chemiluminescent substrate, a phosphate ester of adamantyl dioxetane, undergoes hydrolysis in the presence of alkaline phosphatase to vield an unstable intermediate. The continuous production of this intermediate results in a sustained emission of light, thus improving precision by providing a window for multiple readings. The bound complex - and thus also the photon output as measured by the luminometer - is inversely proportional to the concentration of cannabinoids in the sample.
Here's a breakdown of the acceptance criteria and study information based on the provided document:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Relative Sensitivity (vs. Roche Abuscreen Online THC) | 99.2% |
| Relative Specificity (vs. Roche Abuscreen Online THC) | 98.2% |
| Relative Sensitivity (vs. Abbott AxSYM Cannabinoids) | 96.3% |
| Relative Specificity (vs. Abbott AxSYM Cannabinoids) | 99.0% |
Note: The document compares the IMMULITE® Cannabinoids assay against two predicate devices. The acceptance criteria are implicitly defined by the performance of these predicate devices as demonstrated by the presented comparison data. No explicit numerical acceptance thresholds are stated, but the intent is to show performance "as well as or better than" the legally marketed devices.
Study Details
2. Sample size used for the test set and data provenance
- Sample Size: A total of 456 urine samples were used for the method comparison study.
- Data Provenance: Randomly selected drug-free and drug-containing urine samples were obtained from a hospital in Switzerland. The samples were tested on-site. This indicates a retrospective study design using clinical samples.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- The document does not specify the number of experts or their qualifications for establishing ground truth regarding the presence or absence of cannabinoids.
4. Adjudication method for the test set
- The document does not explicitly state an adjudication method. However, for discrepant results between the IMMULITE® Cannabinoids assay and the predicate devices, GC/MS (Gas Chromatography/Mass Spectrometry) was used as a confirmatory method to resolve these discrepancies. For example, cases where IMMULITE® was negative and Roche was positive were confirmed by GC/MS (found non-detectable). Similarly, for discrepancies with Abbott AxSYM, GC/MS was used. This implies an ad-hoc adjudication involving a gold standard (GC/MS) for discordant results.
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
- No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This device is a chemiluminescent enzyme immunoassay for laboratory use, not an AI-assisted diagnostic tool for human readers. Therefore, the concept of human reader improvement with/without AI assistance does not apply.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done
- Yes, a standalone performance study was done. The entire method comparison against the predicate devices (Roche Abuscreen Online THC and Abbott AxSYM Cannabinoids) demonstrates the performance of the IMMULITE® Cannabinoids assay as an automated, instrument-based test, without human intervention in the interpretation of the primary result (though laboratory personnel operate the instrument and perform steps like sample loading). The performance metrics (sensitivity, specificity) are for the device itself.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- The primary ground truth for resolving discrepancies between the IMMULITE® Cannabinoids assay and the predicate devices was GC/MS (Gas Chromatography/Mass Spectrometry). GC/MS is considered a gold standard for drug confirmation and quantification.
8. The sample size for the training set
- The document does not specify a training set sample size. This type of device (immunoassay) is typically developed and validated using a range of samples during its initial design, but the provided study focuses on a clinical test set for performance validation, not on a separate "training set" in the context of machine learning.
9. How the ground truth for the training set was established
- As no specific "training set" as understood in machine learning is mentioned, this information is not applicable and not provided in the document. The development of such an assay would involve extensive analytical validation against known standards and characterized samples, but this is distinct from a ground-truthed training set for a machine learning model.
§ 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).