(41 days)
Syntron's QuikStrip One Step Opiates assay is a rapid, qualitative, competitive binding immunoassay for the determination of Opiates in urine at the cutoff level of 300 ng/ml. The test provides only preliminary data which should be confirmed by other methods such as gas chromatography/mass spectrophotometry (GC/MS). Clinical considerations and professional judgment should be applied to any drug of abuse test result, particularly when preliminary positive results are indicated6. Syntron's QuikStrip One Step Opiates Test is not intended to monitor drug levels, but only to screen urines for the presence of Opiates and its metabolites.
Syntron's QuikStrip One Step Opiates Test consists of a chromatographic absorbent device in which the drug or drug metabolites in the sample compete with a drug conjugate immobilized on a porous membrane support for the limited antibody sites. As the test sample flows up through the absorbent device, the labeled antibody-dye conjugate binds to the free drug in the specimen forming an antibody:antigen complex. This complex competes with immobilized antigen conjugate in the positive reaction zone and will not produce a magenta color band when the drug is above the detection level of 300 ng/ml. Unbound dye conjugate binds to the reagent in the control zone, producing a magenta color band, demonstrating that the reagents and device are functioning correctly.
Here's an analysis of the provided text regarding the QuikStrip One Step Opiates Test, structured to answer your questions:
Acceptance Criteria and Device Performance Study for QuikStrip One Step Opiates Test
1. Table of Acceptance Criteria and Reported Device Performance
The submission does not explicitly state pre-defined acceptance criteria values for sensitivity, specificity, and accuracy. Instead, the device performance is reported and implied to meet the necessary standards for substantial equivalence.
| Performance Metric | Implied Acceptance Criteria (Implicit) | Reported Device Performance | Comments |
|---|---|---|---|
| Relative Sensitivity | High (e.g., >90-95%) | 100% | For positive samples compared to Syva EMIT® II and confirmed by GC/MS. |
| Relative Specificity | High (e.g., >90-95%) | 100% | For negative samples compared to Syva EMIT® II and confirmed by GC/MS. |
| Accuracy | High (e.g., >90-95%) | 100% | Overall agreement with Syva EMIT® II and confirmed by GC/MS. |
| False Positives | Zero | Zero | Implied as no false positives were found. |
| False Negatives | Zero | Zero | Implied as no false negatives were found. |
Note: The acceptance criteria are "implied" because the document states the results of the study (100% for all metrics) and then concludes that these results did not show any false positives or negatives, suggesting these perfect scores were sufficient for acceptance.
2. Sample Size and Data Provenance for the Test Set
- Sample Size for Test Set:
- Clinical Trial: 298 samples.
- In-house testing: The exact number of samples for in-house testing is not specified, but it was conducted prior to the clinical trial. It states "samples documented to be positive by GC/MS," suggesting a subset of confirmed positive samples were used.
- Data Provenance: The document does not explicitly state the country of origin. Given the company is Syntron Bioresearch, Inc. (Carlsbad, California) and the consultant is also US-based, it is highly probable the data is of US origin. The study was prospective in the sense of a clinical trial, but the confirmation by GC/MS would have been performed after the initial screening.
3. Number of Experts and Qualifications for Ground Truth of the Test Set
The document does not directly mention the use of "experts" to establish ground truth in the traditional sense of medical image or diagnosis interpretation. Instead, the ground truth was established by laboratory methods.
- Number of Experts: Not applicable in this context.
- Qualifications of Experts: Not applicable, as the ground truth was based on laboratory assays, not expert interpretation.
4. Adjudication Method for the Test Set
Adjudication methods like 2+1 or 3+1 are typically used when human interpretation is involved, especially in cases of disagreement. Since the ground truth for this device (an immunoassay for opiates) was established by laboratory comparison to a predicate device (Syva EMIT® II) and then confirmed by a gold standard method (GC/MS), an "adjudication method" as you've defined it is not applicable. Any disagreements between the QuikStrip and EMIT II would have been resolved by GC/MS.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This type of study is relevant for devices that are interpreted by human readers (e.g., radiologists, pathologists) to assess how human performance is affected by the device (e.g., AI assistance). The QuikStrip test is a rapid, qualitative immunoassay that provides a direct result (visual color band), not requiring human interpretation in a way that would lend itself to an MRMC study.
6. Standalone (Algorithm Only) Performance Study
Yes, a standalone performance study was done. The entire study described evaluates the QuikStrip device's performance (an "algorithm" in a broad sense, meaning the assay's biochemical mechanism) independently. Its results are compared to the predicate device (Syva EMIT® II) and a gold standard (GC/MS) without human-in-the-loop performance influencing the primary metrics of sensitivity, specificity, and accuracy. The device itself produces the qualitative result.
7. Type of Ground Truth Used
The ground truth for the test set was established using a hierarchical approach:
- Primary Comparison: Against the Syva EMIT® II assay (a legally marketed predicate device).
- Confirmation Standard (Gold Standard): All positive samples (by either screening method) were confirmed by Gas Chromatography/Mass Spectrometry (GC/MS). GC/MS is considered the definitive gold standard for drug detection and quantification in forensic and clinical toxicology.
8. Sample Size for the Training Set
The document does not provide information regarding a distinct "training set" for the device. For a rapid immunoassay like the QuikStrip, the development process might involve initial R&D and optimization using various samples, but it's not typically structured with separate, formally defined "training," "validation," and "test" sets in the same way an AI/ML algorithm would be. The reported data relates to the final performance evaluation of the device.
9. How Ground Truth for the Training Set Was Established
As no distinct training set is identified, the method for establishing its ground truth is not mentioned in the provided text. If an implicit training was involved during product development, it would likely have relied on similar analytical methods (e.g., GC/MS or other established methods) to ensure the assay's reagents and design performed as intended during optimization.
§ 862.3650 Opiate test system.
(a)
Identification. An opiate test system is a device intended to measure any of the addictive narcotic pain-relieving opiate drugs in blood, serum, urine, gastric contents, and saliva. An opiate is any natural or synthetic drug that has morphine-like pharmocological actions. The opiates include drugs such as morphine, morphine glucoronide, heroin, codeine, nalorphine, and meperedine. Measurements obtained by this device are used in the diagnosis and treatment of opiate use or overdose and in monitoring the levels of opiate administration to ensure appropriate therapy.(b)
Classification. Class II (special controls). An opiate 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).