(195 days)
The Methadone assay is used for the qualitative analysis of methadone in human urine with a cutoff of 300 ng/mL for use in clinical laboratories. Measurements obtained by this device are used in the diagnosis and treatment of methadone use or overdose.
The Methadone assay is calibrated with methadone and is specific for methadone.
The Methadone assay 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 spectrometry (GC/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 used.
Methadone is an in vitro diagnostic assay for the qualitative analysis of methadone in human urine. The assay is a homogeneous enzyme immunoassay with a 300 ng/mL cutoff. The assay is based on competition between drug in the specimen and drug labeled with the enzyme glucose-6-phosphate dehydrogenase (G6PDH) for antibody binding sites. Enzyme activity decreases upon binding to the antibody, so the drug concentration in the specimen can be measured in terms of enzyme activity.
Here's an analysis of the provided text regarding the Methadone assay, outlining the acceptance criteria and study details:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criterion (Implicit) | Reported Device Performance |
|---|---|
| Substantial equivalence to predicate device (Emit® II Methadone assay on SYVA®-30R Analyzer) | Demonstrated by 100% agreement in method comparison. |
| Acceptable correlation with GC/MS (confirmatory method) | 99% agreement with GC/MS. |
| Precision (Within-run and total at various control levels) | Total %CV for controls: range from 0.63% to 0.74%. |
| Qualitative analysis of methadone in human urine with a 300 ng/mL cutoff | Device performs qualitative analysis with a 300 ng/mL cutoff. |
| Limit of Detection (Sensitivity) | 20 ng/mL |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The document mentions "clinical specimens tested ranged from 231.0 to 40,190.0 ng/mL" for the GC/MS comparison, but the exact number of clinical specimens is not explicitly stated. For the comparison with the predicate device, it also does not explicitly state the number of samples used, only that there was 100% agreement.
- Data Provenance: The document does not specify the country of origin of the data or whether the study was retrospective or prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Number of Experts: Not applicable. The ground truth was established by laboratory methods, not expert human review.
- Qualifications of Experts: Not applicable.
4. Adjudication Method for the Test Set
- Adjudication Method: Not applicable. The ground truth was established by laboratory methods (predicate device and GC/MS), not by human adjudication of opinions.
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 Comparative Effectiveness Study: No, an MRMC study was not done. This device is an in vitro diagnostic assay, not an AI-based image analysis or diagnostic assist tool for human readers.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Standalone Performance: Yes, the described performance (concordance with predicate and GC/MS, precision, limit of detection) represents the standalone performance of the Methadone assay as an algorithm/device, without human intervention in the result generation.
7. The Type of Ground Truth Used
- Type of Ground Truth:
- Predicate Device Comparison: The Emit® II Methadone assay on the SYVA®-30R Analyzer served as a reference standard for establishing substantial equivalence.
- Confirmatory Method: Gas Chromatography/Mass Spectrometry (GC/MS) was used as the "gold standard" or confirmatory method to establish the accuracy of the device.
8. The Sample Size for the Training Set
- Training Set Sample Size: This information is not provided in the document. The document describes performance studies, but not the development or training of the assay. For an enzyme immunoassay, there isn't typically a "training set" in the same sense as machine learning algorithms. The assay design and calibration are based on known chemical properties and concentrations of methadone.
9. How the Ground Truth for the Training Set was Established
- Ground Truth for Training Set: This information is not provided and is not directly applicable in the context of a traditional enzyme immunoassay. The "ground truth" for calibrating such an assay would typically involve using precisely quantified standards of methadone.
§ 862.3620 Methadone test system.
(a)
Identification. A methadone test system is a device intended to measure methadone, an addictive narcotic pain-relieving drug, in serum and urine. Measurements obtained by this device are used in the diagnosis and treatment of methadone use or overdose and to determine compliance with regulations in methadone maintenance treatment.(b)
Classification. Class II (special controls). A methadone 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).