(57 days)
Syntron's QuikStrip One Step Barbiturate assay is a rapid, qualitative, competitive binding immunoassay for the determination of Barbiturate in urine at the cutoff level of 200 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 indicated. Syntron's QuikStrip One Step Barbiturate Test is not intended to monitor drug levels, but only to screen urines for the presence of Barbiturate and its metabolites.
Syntron's QuikStrip One Step Barbiturate 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 200 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.
1. Table of Acceptance Criteria and Reported Device Performance:
| Metric | Acceptance Criteria (Implied by Predicate) | QuikStrip Performance (Clinical Trial) |
|---|---|---|
| Relative Sensitivity | Not explicitly stated, but 100% by in-house | 100% |
| Relative Specificity | Not explicitly stated, but 100% by in-house | 99.41% |
| Accuracy | Not explicitly stated, but 100% by in-house | 99.61% |
| False Positives | Minimize, ideally 0 | 2 (due to adulterant) |
| False Negatives | Minimize, ideally 0 | 0 |
Note: The document implies acceptance criteria by comparing the device's performance to the predicate device (Syva EMIT® /200 II) and stating that the results are not significantly different. The in-house testing results, which also achieved 100% for sensitivity, specificity, and accuracy against GC/MS-confirmed samples, further suggest this as a benchmark.
2. Sample Size and Data Provenance:
- Clinical Trial Test Set Sample Size: 307 samples.
- Data Provenance: The document does not explicitly state the country of origin. It refers to "in-house testing" by the sponsor (Syntron Bioresearch, Inc. in Carlsbad, California) and a "clinical trial site." This suggests US-based data, but it is not definitively stated.
- Retrospective or Prospective: Not explicitly stated, but given the nature of a "clinical trial," it is more likely to be prospective for the 307 samples. The "in-house testing" against samples documented as positive by GC/MS could be retrospective analysis of already collected samples.
3. Number of Experts and Qualifications for Ground Truth:
- The document does not explicitly state the number of experts or their qualifications for establishing ground truth, beyond using "GC/MS" as the definitive confirmation method.
4. Adjudication Method for the Test Set:
- The document does not describe an adjudication method for the test set. The direct comparison is made against GC/MS (200 ng/ml) for all positive samples. This implies GC/MS served as the definitive arbiter.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. The device is a "QuikStrip One Step Barbiturate Test," which is a rapid, qualitative immunoassay. It does not involve human readers interpreting complex images or data in a way that an MRMC study would typically assess.
6. Standalone Performance:
- Yes, a standalone (algorithm only without human-in-the-loop performance) study was performed. The described "in-house testing" and "clinical trial" directly assess the performance of the QuikStrip device itself (relative sensitivity, relative specificity, accuracy) against a reference standard (Syva EMIT® /200 II and GC/MS). The device provides a visual result (color band) and does not require complex human interpretation that would necessitate a "human-in-the-loop" assessment for primary validation.
7. Type of Ground Truth Used:
- The primary ground truth used for confirmation, especially for positive samples, was Gas Chromatography/Mass Spectrometry (GC/MS) at a cutoff of 200 ng/ml.
- The device's performance was also compared against the Syva EMIT® /200 II as a predicate device, which itself is a screening method.
8. Sample Size for the Training Set:
- The document does not provide information on a specific training set sample size. This is a rapid diagnostic test, and the development process might involve internal calibration and development-phase testing rather than a distinct, formal "training set" like in machine learning models.
9. How the Ground Truth for the Training Set Was Established:
- As no specific "training set" is mentioned, the method for establishing its ground truth is not described. However, it's reasonable to infer that during the development of the immunoassay, internal validation and optimization would rely on similarly established ground truth using methods like GC/MS to ensure the test accurately detects barbiturates at the specified cutoff.
§ 862.3150 Barbiturate test system.
(a)
Identification. A barbiturate test system is a device intended to measure barbiturates, a class of hypnotic and sedative drugs, in serum, urine, and gastric contents. Measurements obtained by this device are used in the diagnosis and treatment of barbiturate use or overdose and in monitoring levels of barbiturate to ensure appropriate therapy.(b)
Classification. Class II (special controls). A barbiturate 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).