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510(k) Data Aggregation
(55 days)
The DRI Benzodiazepine Assay is a homogeneous enzyme immunoassay intended for the qualitative and/or semi-quantitative determination of the presence of benzodiazepines and their metabolites in human urine at a cutoff concentration of 200 ng/mL. The assay is intended to be used in laboratories a simple and rapid analytical screening procedure to detect benzodiazepines in human urine. The assay is designed for use with a number of clinical chemistry analyzers. This assay is calibrated against Oxazepam. This product is intended to be used by trained professionals only.
The semi-quantitative mode is for the purpose of enabling laboratories to determine an appropriate dilution of the specimen for confirmation by a confirmatory method such as Liquid Chromatography/tandem mass spectrometry (LC-MS/MS) or permitting laboratories to establish quality control procedures.
The assay provides only a preliminary analytical test result. A more specific alternative chemical must be used to obtain a confirmed analytical result. Gas chromatography/ mass spectrometry (GC/MS) or Liquid chromatography/tandem mass spectrometry (LC-MS/MS) is the preferred confirmatory method.
Clinical and professional judgment should be applied to any drug of abuse test result, particularly when preliminary results are used. For In Vitro Diagnostic Use Only.
The DRI Benzodiazepine Assay is a homogeneous enzyme immunoassay with liquid ready-to-use reagents. The assay uses a specific antibody which can detect most benzodiazepines and their metabolites in urine. The assay is based on the competition of an enzyme glucose- 6-phosphate dehydrogenase (G6PDH) labeled drug and the drug from the urine sample for a fixed amount of specific antibody binding sites. In the absence of free drug from the sample, the enzyme-labeled drug is bound by the specific antibody and the enzyme activity is inhibited. This phenomenon creates a relationship between drug concentration in urine and the enzyme activity. The enzyme G6PDH activity is determined spectrophotometrically at 340 nm by measuring its ability to convert nicotinamide adenine dinucleotide (NAD) to NADH.
The assay consists of reagents A and E.
Reagent A: Contains sheep polyclonal anti-benzodiazepine antibodies, glucose-6-phosphate (G6P) and nicotinamide adenine dinucleotide (NAD) in Tris buffer with sodium azide as a preservative.
Reagent E: Contains benzodiazepine derivative labeled with glucose-6-phosphate dehydrogenase (G6PDH) in Tris buffer with sodium azide as a preservative.
The provided document describes the analytical performance verification of the DRI Benzodiazepine Assay, an in vitro diagnostic device, and not an AI/ML-enabled medical device. Therefore, many of the requested categories (e.g., number of experts, adjudication methods, MRMC studies, standalone performance of an algorithm, training set details) are not applicable to this type of device and study.
However, I can extract the acceptance criteria and reported performance for the analytical studies conducted, which demonstrate the device's substantial equivalence to a predicate device.
Device Name: DRI Benzodiazepine Assay
Regulation Number: 21 CFR 862.3170
Regulation Name: Benzodiazepine test system
Regulatory Class: Class II
Product Code: JXM
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state "acceptance criteria" in a tabulated format for each study, but rather presents the results of various analytical performance studies which are implicitly used to demonstrate the device's suitability and substantial equivalence. I will infer the acceptance criteria from typical requirements for such in vitro diagnostic assays and the presented results.
| Study Parameter | Implied Acceptance Criterion (Typical for IVD) | Reported Device Performance |
|---|---|---|
| Precision (Qualitative) | All replicates at ±25%, ±50%, ±75%, ±100% of cutoff show consistent classification; some variability expected at cutoff (200 ng/mL). | At -100% (0 ng/mL), -75% (50 ng/mL), -50% (100 ng/mL), -25% (150 ng/mL): 80/80 (100%) Negative. At +25% (250 ng/mL), +50% (300 ng/mL), +75% (350 ng/mL), +100% (400 ng/mL): 80/80 (100%) Positive. At 100% cutoff (200 ng/mL): 16/64 (20%/80%) Negative/Positive. |
| Precision (Semi-Quantitative) | Similar to qualitative, with expected distribution around cutoff. | At -100% (0 ng/mL), -75% (50 ng/mL), -50% (100 ng/mL), -25% (150 ng/mL): 80/80 (100%) Negative. At +25% (250 ng/mL), +50% (300 ng/mL), +75% (350 ng/mL), +100% (400 ng/mL): 80/80 (100%) Positive. At 100% cutoff (200 ng/mL): 27/53 (33.75%/66.25%) Negative/Positive. |
| Spike Recovery (Qualitative) | Accurate classification of samples below/above cutoff. | 150 ng/mL (Below Cutoff): 20/20 (100%) Negative. 250 ng/mL (Above Cutoff): 20/20 (100%) Positive. |
| Analytical Recovery and Linearity | Recoveries within a generally accepted range (e.g., 80-120%) across the tested range. Implies accuracy and proportionality to concentration. | Recovery between 98.1% and 113.8% for Oxazepam concentrations ranging from 100 ng/mL to 1000 ng/mL. (Level 1, 0 ng/mL, N/A recovery). |
| Method Comparison and Accuracy (Qualitative) | High overall agreement with confirmatory method (LC-MS/MS), particularly for positive and negative agreement. | Overall agreement with LC-MS/MS: 96.2% (102/106 samples). Negative agreement: 92.9% (52/56). Positive agreement: 100% (50/50). Four discordant samples identified as positive by the device but below cutoff by LC-MS/MS were due to significant levels of benzodiazepine metabolites not quantified by the parent compound concentration in LC-MS/MS, which the immunoassay cross-reacts with. This is expected behavior for an immunoassay designed to detect metabolites. |
| Method Comparison and Accuracy (Semi-Quantitative) | High overall agreement with confirmatory method (LC-MS/MS), similar to qualitative. | Overall agreement with LC-MS/MS: 96.2% (102/106 samples). Negative agreement: 92.9% (52/56). Positive agreement: 100% (50/50). Same four discordant samples as qualitative, explained by metabolite cross-reactivity. |
| Specificity (Cross-reactivity with structurally related compounds) | Detection of various benzodiazepine compounds and their metabolites at specified concentrations. | Many compounds showed excellent cross-reactivity (e.g., α-Hydroxyalprazolam, Alprazolam, Estazolam, Diazepam, Flunitrazepam, Nordiazepam, Oxazepam) with cross-reactivity >90% (e.g., 91-200%). Some showed lower but acceptable cross-reactivity (e.g., 7-Aminoclonazepam: 8%; Chlordiazepoxide: 29%; Lorazepam: 29%). Glucuronides conjugate forms typically show very low cross-reactivity (<0.4%). |
| Specificity (Interference from structurally unrelated compounds) | No significant interference with accurate classification of low and high controls. | All tested compounds (a wide range of common drugs and substances like Acetaminophen, Amphetamine, Caffeine, Codeine, Ibuprofen, Morphine, etc.) did not interfere with the accurate classification of the spiked low (Negative) and high (Positive) Oxazepam controls, even at high concentrations (e.g., 100,000 ng/mL to 1,000,000 ng/mL). |
| Interference (pH and Endogenous Substances) | No significant interference from tested pH levels or endogenous substances. | All tested pH levels (3.0-11.0) and endogenous substances (Acetone, Ascorbic acid, Creatinine, Ethanol, Glucose, Hemoglobin, etc.) at high concentrations did not interfere with the accurate classification of spiked low (Negative) and high (Positive) Oxazepam controls. |
| Specific Gravity | No significant interference from urine specific gravity variations. | All tested specific gravity values (1.004 to 1.029) did not interfere with the accurate classification of spiked low (Negative) and high (Positive) Oxazepam controls. |
2. Sample Size Used for the Test Set and Data Provenance
- Precision Studies: 80 replicates per concentration level (2 replicates, twice per day for 20 days). Samples were prepared by spiking Oxazepam into drug-free urine.
- Spike Recovery: 20 replicates for each spiked concentration (150 ng/mL and 250 ng/mL). Samples were prepared by spiking Oxazepam into drug-free urine.
- Analytical Recovery and Linearity: 10 intermediate dilution levels, each run in replicates of five. Samples were prepared by spiking Oxazepam into drug-free urine.
- Method Comparison and Accuracy: 106 patient samples.
- Data Provenance: The document states "One hundred and six patient samples were analyzed...". The country of origin is not explicitly stated, but the submission is to the U.S. FDA, and the company address is Fremont, CA, implying the studies were likely conducted in the US. The samples are referred to as "patient samples," which typically implies retrospective collection for assay validation, but it's not explicitly stated as retrospective or prospective.
- Specificity (Cross-reactivity & Interference): Samples were prepared by adding known amounts of compounds to drug-free negative urine, or spiking controls.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Not Applicable. This is an in vitro diagnostic assay, not an AI/ML-enabled image analysis device. The ground truth for chemical analytes (benzodiazepines) in urine samples is established by a reference analytical method, specifically Gas Chromatography/Mass Spectrometry (GC/MS) or Liquid Chromatography/tandem Mass Spectrometry (LC-MS/MS), which are considered the "gold standard" for drug confirmations in toxicology. No human experts (e.g., radiologists) were involved in establishing the ground truth.
4. Adjudication Method for the Test Set
- Not Applicable. As the ground truth is established by an objective chemical confirmatory method (LC-MS/MS), there is no need for human adjudication of results in the traditional sense seen in imaging studies. Discrepancies between the immunoassay and LC-MS/MS are analyzed scientifically to understand the reason (e.g., cross-reactivity with metabolites, which is precisely what the immunoassay is designed to do).
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
- Not Applicable. This is an in vitro diagnostic (IVD) assay, not an AI/ML diagnostic aid. It does not involve "human readers" in the context of image interpretation or clinical decision-making from an AI output. Its performance is evaluated analytically against a reference method.
6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was done
- Not Applicable. This is an IVD assay. Its performance is inherently "standalone" in the sense that the device itself produces a result (qualitative or semi-quantitative) based on chemical reactions. There is no algorithm in the AI sense, nor a "human-in-the-loop" interaction directly with the assay's output similar to how one might interact with an AI-generated image finding. The results are interpreted by trained professionals.
7. The Type of Ground Truth Used
- Confirmatory Method / Gold Standard: The ground truth for benzodiazepine concentrations in urine samples was established using a "confirmatory method such as Liquid Chromatography/tandem Mass Spectrometry (LC-MS/MS)" (stated in the Indications for Use and the Method Comparison study). This is considered the preferred confirmatory method in toxicology.
8. The Sample Size for the Training Set
- Not Applicable. This is a traditional enzyme immunoassay, not a machine learning model. There is no "training set" in the context of AI/ML. The assay formulation (reagents, antibodies) is developed through biochemical research and optimization, not data-driven machine learning training.
9. How the Ground Truth for the Training Set was Established
- Not Applicable. (See #8). As there is no training set for an AI model, there is no ground truth to be established for it. The "ground truth" (i.e., known concentrations or presence/absence of analytes) for the samples used in analytical validation studies (e.g., linearity, accuracy, specificity) would be established using validated reference methods or precise spiking of known concentrations into a blank matrix.
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