(48 days)
Syntron's QuikStrip One Step Cocaine assay is a rapid, qualitative, competitive binding immunoassay for the determination of Cocaine in urine at the NIDA recommended cutoff of 150 mg/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 indicated. Syntron's QuikStrip 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 QuikStrip 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 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 150 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 the study details for the QuikStrip One Step Cocaine Test, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state 'acceptance criteria' in a formal, numbered list. However, it implicitly uses agreement with a predicate device (Syva EMIT® II) and GC/MS confirmation as benchmarks for performance. I have constructed the "Acceptance Criteria" based on the reported performance that allowed the device to gain 510(k) clearance.
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance (Clinical Trial) |
|---|---|---|
| Relative Sensitivity (Agreement within positive samples) | High (e.g., >95%) | 99.49% |
| Relative Specificity (Agreement within negative samples) | High (e.g., >95%) | 100% |
| Accuracy | High (e.g., >95%) | 99.75% |
Note: The in-house testing showed slightly different results (sensitivity 1.000, specificity 0.9839, accuracy 99.03%). The table above uses the clinical trial results as they represent a more robust dataset.
2. Sample Sizes Used for the Test Set and Data Provenance
- Sample Size for Test Set: 304 samples (for the clinical trial).
- Data Provenance: Not explicitly stated (e.g., country of origin). The study involved a clinical trial, suggesting prospective data collection, though details on the recruitment process are not provided. Given the nature of a 510(k) submission, it is assumed to be retrospective in terms of analyzing collected samples against existing predicate methods and reference methods.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Number of Experts: Not specified.
- Qualifications of Experts: Not specified.
- The primary ground truth for confirmation was GC/MS (Gas Chromatography/Mass Spectrometry), which is an analytical laboratory technique, not a human expert.
- The comparison was primarily against the Syva EMIT® II predicate device, which is an automated immunoassay.
4. Adjudication Method for the Test Set
- Not applicable in the traditional sense for human-expert interpretation.
- Discrepancies between the QuikStrip and EMIT II® were resolved by GC/MS confirmation. Three specific discrepant samples were further analyzed, revealing adulteration that caused false positives in both screening methods.
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, an MRMC comparative effectiveness study was not done.
- This device is a rapid, qualitative immunoassay for drug screening, not an imaging or diagnostic device requiring human interpretation of complex outputs. Therefore, the concept of "human readers improve with AI vs without AI assistance" does not apply here.
6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was done
- Yes, this was a standalone performance study. The QuikStrip One Step Cocaine Test itself is a rapid, self-contained test, and the reported performance metrics (sensitivity, specificity, accuracy) reflect the device's inherent capability to detect cocaine and its metabolites in urine without human "interpretation" beyond reading the color bands according to the instructions. The comparison was to another standalone testing method (EMIT II) and a definitive lab method (GC/MS).
7. The Type of Ground Truth Used
- The ultimate ground truth used for confirmation of positive samples was Gas Chromatography/Mass Spectrometry (GC/MS).
- For the study's initial comparison, the Syva EMIT® II was used as a comparative method, with GC/MS confirming discrepancies.
8. The Sample Size for the Training Set
- The document does not specify a separate training set size. The provided performance data (in-house and clinical trial) likely refer to validation or test sets, not a training set for a machine learning model. This device is a biochemical immunoassay, not an AI/ML algorithm that requires a distinct training phase.
9. How the Ground Truth for the Training Set Was Established
- Not applicable, as this device is not an AI/ML algorithm requiring a training set with established ground truth in the conventional sense. The "ground truth" for the development of such assays typically involves known concentrations of analytes and cross-reactants, and then extensive validation against reference methods like GC/MS. The document refers to "in-house testing" which would have been part of the development and initial validation process, where samples with known cocaine status (often confirmed by GC/MS) would be used.
§ 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).