(64 days)
The Visualine® Barbiturates DipStrip Test is used for qualitative testing for the presence of Secobarbital in urine samples at or above 300 ng/ml. This test provides only a preliminary screening result; a more specific alternative method should be used to confirm the test result. This test is intended for use by medical professionals.
The Visualine® Barbiturates DipStripTest is based on the principle of antigen-antibody complexation and is used for the analysis of Barbiturates and it's metabolites in urine samples. The assay utilizes a competitive immunochromatographic technique involving a sample of test urine delivered in a sample well on the device that holds the porous membrane. When the drug is present in the urine test sample, the drug or drug metabolite competes for the limited antibody sites on the colored microspheres. When an adequate amount of drug is present, it will fill the limited antibody binding sites. This will prevent attachment of the colored microspheres to the probe site on the membrane. Therefore, a positive urine sample will inhibit the formation of precipitin at the probe site. A reference or control line with a secondary antibody reaction is added to the membrane strip to indicate viability of the test. This control line should always be present. A negative urine sample will produce two colored lines and a positive urine sample will show only one, the control line.
Here's a breakdown of the acceptance criteria and study details for the Visualine® Barbiturates DipStrip Test, based on the provided document:
Acceptance Criteria and Device Performance
| Criteria | Acceptance Level (Implied/Reported) | Reported Device Performance |
|---|---|---|
| Sensitivity | Not explicitly stated as a minimum acceptance level, but performance compared to a predicate device. | 94% (95/101) |
| Specificity | Not explicitly stated as a minimum acceptance level, but performance compared to a predicate device. | 95% (95/100) |
| Efficiency | Not explicitly stated as a minimum acceptance level, but performance compared to a predicate device. | 95% (190/201) |
| Detection Level | 300 ng/ml Barbiturates | Detects at 300 ng/ml |
| Sensitivity at 360 ng/ml | Not explicitly stated as a minimum for this specific concentration. | 94% |
| Precision (Reproducibility) | Not explicitly stated (e.g., >X%). | Within run & run to run: >99% |
| Within day & day to day: >99% | ||
| Within lot & lot to lot: >99% | ||
| Stability | Stable until marked expiration date under specified storage conditions. | Tested every three months for up to two years and found stable. |
Study Details
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Sample Size used for the test set and data provenance:
- Sample Size: 201 urine samples (190 correctly identified + 11 misidentified = 201 total). Specifically, 101 samples were positive and 100 were negative according to the predicate device.
- Data Provenance: The samples were "provided by The Lab, Inc." The country of origin is not explicitly stated, but the manufacturer (Sun Biomedical Laboratories, Inc.) is located in Blackwood, NJ, USA, and FDA approval is being sought, suggesting a US context for the study. The study appears to be retrospective, using a collected set of samples.
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Number of experts used to establish the ground truth for the test set and qualifications of those experts:
- This information is not provided in the document. The "ground truth" for correlation was established by comparison to results from the Hitachi Emit® Barbiturates Assay, which is a laboratory-based homogenous enzyme immunoassay. The document does not describe human expert involvement in establishing ground truth for the test set.
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Adjudication method for the test set:
- None specified. The comparison is directly against the results of the Hitachi Emit® Barbiturates Assay.
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If a multi-reader multi-case (MRMC) comparative effectiveness study was done, and what was the effect size of how much human readers improve with AI vs without AI assistance:
- Not applicable. This device is an in-vitro diagnostic dipstrip test for visual color comparison, not an AI-assisted diagnostic tool for human readers. No MRMC study or AI assistance is mentioned.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, effectively. The reported performance (sensitivity, specificity, efficiency) is for the Visualine® Barbiturates DipStrip Test itself, in comparison to the Hitachi Emit® Barbiturates Assay. Although the dipstrip test is read visually, the reported performance metrics reflect the device's ability to produce its result (presence/absence of a line) accurately relative to a reference method, without specifying human variability in reading. The intent of the device is for professional use, implying trained personnel will interpret the visual results.
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The type of ground truth used:
- Reference Method Comparison. The ground truth was established by the results obtained from the Hitachi Emit® Barbiturates Assay, which itself is a commercially available and presumably validated laboratory immunoassay.
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The sample size for the training set:
- The document does not provide information about a separate "training set" for the Visualine® Barbiturates DipStrip Test. This type of immunoassay typically undergoes development and optimization, rather than a machine learning-style training process with a distinct training set. The correlation studies mentioned are evaluation studies.
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How the ground truth for the training set was established:
- As there is no mention of a separate training set, this information is not applicable/not provided. The development of the immunochromatographic test would involve internal validation and optimization against known samples (spiked samples, characterized clinical samples), but these are not formally described as a "training set" with ground truth established in the same way a machine learning algorithm would.
§ 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).