(13 days)
Syntron's QuikPac II One Step Cocaine assay is a rapid, qualitative, competitive binding immunoassay for the determination of Cocaine in urine at the cutoff level of 300 ng/ml (NIDA screening cutoff is 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 QuikPac II One Step Cocaine Test is not intended to monitor drug levels, but only to screen urines for the presence of Cocaine and its metabolites.
Syntron's QuikPac II One Step Cocaine 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 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 a breakdown of the acceptance criteria and study information for the QuikPac II One Step Cocaine Test based on the provided text:
Acceptance Criteria and Device Performance
| Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Relative Sensitivity (Positive Samples) | High agreement with a commercial EIA test and GC/MS for positive samples. | In-house: 1.000 (100%) |
| Clinical Trial: 99.89% | ||
| Relative Specificity (Negative Samples) | High agreement with a commercial EIA test and GC/MS for negative samples. | In-house: 1.000 (100%) |
| Clinical Trial: 100% | ||
| Accuracy | High overall accuracy compared to a commercial EIA test and GC/MS. | In-house: 100% |
| Clinical Trial: 99.56% | ||
| Detection Level | Should detect cocaine at a cutoff of 300 ng/ml. | Confirmed by testing (implied by design and correlation to NIDA cutoff). |
Note on Acceptance Criteria: The document primarily reports the device performance and then states that it "yielded" those results or that "the combined data yielded" them. The exact explicit acceptance criteria are not formally listed, but they are implied by the high performance metrics themselves, suggesting the device successfully met the sponsor's internal standards and what would be expected for a device of this type.
Study Information
1. Sample Size Used for the Test Set and Data Provenance:
- Sample Size: 318 samples (for the clinical trial).
- Data Provenance: The document does not explicitly state the country of origin. It indicates it was an "in-house testing" and a "clinical trial." Given Syntron Bioresearch, Inc. is located in Carlsbad, California, it's reasonable to infer the "in-house" testing was done in the USA and the clinical trial likely also involved US-based samples, though this is not explicitly stated. The nature of the samples for the clinical trial is implied to be urine samples from individuals, presumably collected prospectively or retrospectively and then anonymized. The text does not specify if the clinical trial data was retrospective or prospective.
2. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
- The document does not mention the use of experts to establish the ground truth for the test set in the traditional sense of human review.
- Instead, the ground truth was primarily established through laboratory methods: "All positive samples by either screening method were confirmed by GC/MS."
3. Adjudication Method for the Test Set:
- The primary adjudication method involved GC/MS confirmation for all positive samples from either the QuikPac II or the commercial EIA test.
- For discrepant samples, the text notes an analysis of "2 discrepant samples" where "Two samples were positive by both GC/MS and QuikPac II, but negative for Cocaine by Emit II." This suggests further investigation and comparison with the definitive GC/MS result to understand the nature of discrepancies among the screening methods.
4. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done:
-
No, an MRMC comparative effectiveness study was not done. This device is a rapid, qualitative, competitive binding immunoassay, which does not involve human "readers" interpreting results in the same way an imaging device or diagnostic tool typically would. The "reading" is a simple visual interpretation of color bands, and the focus is on the agreement with laboratory reference methods.
- Effect Size of Human Readers: Not applicable since an MRCM study was not performed.
5. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, the performance reported is essentially a "standalone" or "device-only" performance when compared to reference methods. While a human visually interprets the color bands, the device's inherent sensitivity, specificity, and accuracy are being evaluated against the gold standard (GC/MS) and a predicate device (commercial EIA). There's no "human-in-the-loop" AI component to evaluate.
6. The Type of Ground Truth Used:
- Gas Chromatography/Mass Spectrometry (GC/MS): This was the definitive ground truth for confirming the presence or absence of cocaine and its metabolites, especially for positive samples and discrepant results.
- Commercial EIA Test for Cocaine: This served as a comparative screening method against which the QuikPac II device's performance was initially measured. While not the absolute ground truth, it was used as a benchmark, with GC/MS as the ultimate arbiter for confirmation.
7. The Sample Size for the Training Set:
- The document does not provide information regarding a separate "training set" size. This type of immunoassay device is developed and validated through laboratory testing and clinical trials rather than through machine learning models that require distinct training and test sets.
8. How the Ground Truth for the Training Set was Established:
- Since there's no explicitly mentioned "training set" in the context of a machine learning model, this question is not applicable. The device's development would have involved extensive R&D and optimization based on known concentrations of cocaine and its metabolites, with performance verified against laboratory standards (likely including GC/MS) throughout the design and optimization phases, which could be considered an iterative development process rather than a formal "training set."
§ 862.3250 Cocaine and cocaine metabolite test system.
(a)
Identification. A cocaine and cocaine metabolite test system is a device intended to measure cocaine and a cocaine metabolite (benzoylecgonine) in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of cocaine use or overdose.(b)
Classification. Class II (special controls). A cocaine and cocaine metabolite 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).