(56 days)
The LZI Opiate 2000 Enzyme Immunoassay is intended for the qualitative and semiquantitative determination of morphine in human urine at the cutoff value of 2000 ng/mL. The assay is designed for professional use with a number of automated clinical chemistry analyzers.
The semi-quantitative mode is for purposes of (1) enabling laboratories to determine an appropriate dilution of the specimen for confirmation by a confirmatory method such as GCMS and LCMS or (2) permitting laboratories to establish quality control procedures.
The LZI Opiate 2000 Drugs of Abuse (DAU) Calibrators are for use as calibrators in the qualitative and semi-quantitative calibration of the LZI Opiate 2000 Enzyme Immunoassay at a cutoff value of 2000 ng/mL.
The LZI Opiate 2000 Drugs of Abuse (DAU) Controls are for use as assayed quality control materials to monitor the precision of the LZI Opiate 2000 Enzyme Immunoassay at a cutoff value of 2000 ng/mL.
The assay provides only a preliminary analytical result: A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. Gas or liquid chromatography/mass spectrometry (GC/MS or LC/MS) is the preferred confirmatory method. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary test result is positive.
The LZI Opiate 2000 assay is a homogeneous enzyme immunoassay with ready-to-use liquid reagents. The assay is based on competition between drug in the sample and drug labeled with the enzyme glucose-6-phosphate dehydrogenase (G6PDH) for a fixed amount of antibody in the reagent. Enzyme activity decreases upon binding to the antibody, and the drug concentration in the sample is measured in terms of enzyme activity. In the absence of drug in the sample, morphine-labeled G6PDH conjugate is bound to antibody, and the enzyme activity is inhibited. On the other hand, when free drug is present in the sample, antibody would bind to free drug; the unbound morphinelabeled G6PDH then exhibits its maximal enzyme activity. Active enzyme converts nicotinamide adenine dinucleotide (NAD) to NADH, resulting in an absorbance change that can be measured spectrophotometrically at 340 nm.
The LZI Opiate 2000 Enzyme Immunoassay is a kit comprised of two reagents, an R1 and R2, which are bottled separately but sold together within the kit.
The R1 solution contains mouse monoclonal anti-morphine antibody, glucose-6phosphate (G6P) nicotinamide adenine dinucleotide (NAD), stabilizers, and sodium azide (0.09%) as a preservative. The R2 solution contains glucose-6-phosphate dehydrogenase (G6PDH) labeled with morphine in buffer with sodium azide (0.09%) as preservative.
The LZI Opiate 2000 Enzyme Immunoassay calibrators and controls designated for use at the 2000 ng/mL cutoff contain 0, 1000, 1500, 2000, 2500, 4000, and 6000 ng/mL of morphine in human urine with sodium azide (0.09%) as preservative. These five calibrators and two controls are sold as individual bottles.
Acceptance Criteria and Device Performance for LZI Opiate 2000 Enzyme Immunoassay
This document outlines the acceptance criteria and the study results demonstrating the performance of the LZI Opiate 2000 Enzyme Immunoassay.
1. Table of Acceptance Criteria and Reported Device Performance
The provided document details the precision and qualitative/semi-quantitative performance of the LZI Opiate 2000 Enzyme Immunoassay. While explicit acceptance criteria are not listed as separate entries (e.g., "accept if Positive Predictive Agreement > X%"), the performance characteristics presented are those that would be assessed against internal or regulatory standards for such a device. For this summary, we interpret the reported performance of the predicate device as an implicit benchmark, and the new device aims to demonstrate comparable or superior performance.
Implicit Acceptance Criteria (based on predicate equivalence and established test performance expectations):
- Precision: Acceptable within-run and total precision (low %CV) across various concentrations, particularly around the cutoff.
- Qualitative/Semi-Quantitative Agreement: High agreement with confirmed GC/MS or LC/MS results for both positive and negative samples.
- Limit of Detection: Ability to reliably detect opiate at a specified low concentration.
- Linearity: Reportable linear range of detection for semi-quantitative use.
- Specificity/Lack of Interference: Absence of significant cross-reactivity or interference from endogenous compounds.
Reported Device Performance (LZI Opiate 2000 Enzyme Immunoassay for Hitachi 717 Analyzer):
| Performance Metric | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Precision (Semi-Quantitative) | Low % CV for within-run and total precision across concentrations | Within-Run %CV: |
| • 0 ng/mL: 36.6% | ||
| • 500 ng/mL: 4.1% | ||
| • 1000 ng/mL: 2.4% | ||
| • 1500 ng/mL: 1.3% | ||
| • 2000 ng/mL: 1.6% | ||
| • 2500 ng/mL: 1.9% | ||
| • 3000 ng/mL: 2.9% | ||
| • 3500 ng/mL: 1.8% | ||
| • 4000 ng/mL: 2.1% | ||
| Total Precision %CV: | ||
| • 0 ng/mL: 39.6% | ||
| • 500 ng/mL: 4.9% | ||
| • 1000 ng/mL: 2.4% | ||
| • 1500 ng/mL: 1.4% | ||
| • 2000 ng/mL: 1.9% | ||
| • 2500 ng/mL: 1.9% | ||
| • 3000 ng/mL: 2.9% | ||
| • 3500 ng/mL: 2.0% | ||
| • 4000 ng/mL: 2.4% | ||
| Qualitative Agreement (Semi-Quant) | High agreement with confirmed results | At 2000 ng/mL Cutoff: |
| Within Run (N=22 per concentration): | ||
| • 0, 500, 1000, 1500 ng/mL: 22 Negative | ||
| • 2000 ng/mL (0% of cutoff): 18 Positive / 4 Negative | ||
| • 2500, 3000, 3500, 4000 ng/mL: 22 Positive | ||
| Total Precision (N=88 per concentration): | ||
| • 0, 500, 1000, 1500 ng/mL: 88 Negative | ||
| • 2000 ng/mL (0% of cutoff): 59 Positive / 29 Negative | ||
| • 2500, 3000, 3500, 4000 ng/mL: 88 Positive | ||
| Precision (Qualitative - mA/min) | Low % CV for within-run and total precision across concentrations | Within-Run %CV: |
| • 0 ng/mL: 0.7% | ||
| • 500 ng/mL: 0.6% | ||
| • 1000 ng/mL: 0.4% | ||
| • 1500 ng/mL: 0.4% | ||
| • 2000 ng/mL: 0.7% | ||
| • 2500 ng/mL: 0.4% | ||
| • 3000 ng/mL: 0.7% | ||
| • 3500 ng/mL: 0.6% | ||
| • 4000 ng/mL: 0.5% | ||
| Total Precision %CV: | ||
| • 0 ng/mL: 0.8% | ||
| • 500 ng/mL: 0.8% | ||
| • 1000 ng/mL: 0.8% | ||
| • 1500 ng/mL: 0.7% | ||
| • 2000 ng/mL: 0.9% | ||
| • 2500 ng/mL: 0.7% | ||
| • 3000 ng/mL: 0.9% | ||
| • 3500 ng/mL: 0.7% | ||
| • 4000 ng/mL: 0.6% | ||
| Qualitative Agreement (Qualitative) | High agreement with confirmed results | At 2000 ng/mL Cutoff: |
| Within Run (N=22 per concentration): | ||
| • 0, 500, 1000, 1500 ng/mL: 22 Negative | ||
| • 2000 ng/mL (0% of cutoff): 9 Positive / 13 Negative | ||
| • 2500, 3000, 3500, 4000 ng/mL: 22 Positive | ||
| Total Precision (N=88 per concentration): | ||
| • 0, 500, 1000, 1500 ng/mL: 88 Negative | ||
| • 2000 ng/mL (0% of cutoff): 33 Positive / 55 Negative | ||
| • 2500, 3000, 3500, 4000 ng/mL: 88 Positive | ||
| Limit of Detection (LoD) | Ability to confidently detect at low concentrations | 200 ng/mL (Lowest concentration differentiated from negative urine with 95% confidence) |
| Linearity | Strong linear correlation across the relevant range | y = 1.078x - 85.072, r² = 0.993 for range 0 - 6000 ng/mL |
| Clinical Sample Method Comparison | High agreement for positive and negative samples | Semi-Quantitative Data: 96.49% agreement with positive, 93.55% agreement with negative samples |
| Qualitative Data: 96.49% agreement with positive, 96.77% agreement with negative samples | ||
| Interference/Specificity | No significant undesired interferences | No significant undesired cross-reactants or endogenous substance interference was observed. |
2. Sample Size and Data Provenance for the Test Set
The document describes test data from different studies:
- Precision Studies: A total of 88 determinations were performed for each concentration level (0, 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000 ng/mL) for both semi-quantitative and qualitative modes. These were laboratory-prepared samples. The provenance of the data (country of origin) is not explicitly stated, but it's likely part of the manufacturer's internal validation. Given these are defined spike levels, the data is prospective and controlled.
- Method Comparison - Clinical Samples: 150 clinical unaltered samples were used. The document does not specify the country of origin but implies they are real-world samples. This data is retrospective, as it compares the device's performance against existing samples confirmed by another method.
3. Number of Experts and Qualifications for Ground Truth
- Precision Studies: The ground truth for the precision studies was established by known concentrations of morphine spiked into urine. This does not involve human experts in establishing the "ground truth" concentrations themselves but relies on accurate laboratory preparation and measurement of these spiked samples.
- Method Comparison - Clinical Samples: The ground truth for the 150 clinical samples was established using a "more specific alternative chemical method," specifically Gas or liquid chromatography/mass spectrometry (GC/MS or LC/MS). These are established analytical methods. The document does not mention the number or specific qualifications of human experts (e.g., laboratory personnel, clinical chemists) who performed these confirmatory tests, as the ground truth is derived from the analytical result of the GC/MS or LC/MS.
4. Adjudication Method for the Test Set
- Precision Studies: No adjudication method is described beyond the direct measurement of instrument responses to samples with known concentrations.
- Method Comparison - Clinical Samples: For the clinical samples, an adjudication method is not explicitly stated. The comparison is made between the LZI Opiate 2000 Enzyme Immunoassay result and the GC/MS or LC/MS result. Discrepancies would typically be reviewed by laboratory personnel, but a formal multi-reader adjudication process (e.g., 2+1) is not mentioned as it's a comparison to a definitive analytical method, not human interpretation.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No Multi-Reader Multi-Case (MRMC) comparative effectiveness study was done. This device is an in-vitro diagnostic assay, not an imaging AI device that assists human readers. Therefore, the concept of "human readers improve with AI vs without AI assistance" is not applicable here.
6. Standalone Performance Study
Yes, a standalone performance study was done. The entire performance characterization (Precision, Qualitative/Semi-Quantitative Results, Limit of Detection, Linearity, and Method Comparison with Clinical Samples) describes the performance of the LZI Opiate 2000 Enzyme Immunoassay algorithm only (the assay itself) without human interpretation in the workflow, aside from standard laboratory procedures for running the test. The "Immunoassay Result" reported in the tables is the output of the device.
7. Type of Ground Truth Used
- For controlled precision and linearity studies, the ground truth was based on known concentrations of morphine in spiked urine samples.
- For the clinical sample method comparison, the ground truth was analytical confirmation by Gas or liquid chromatography/mass spectrometry (GC/MS or LC/MS), which is considered the gold standard for drug confirmation in such contexts.
8. Sample Size for the Training Set
The document does not explicitly mention a "training set" in the context of an algorithm or machine learning model. This device is a homogeneous enzyme immunoassay, a biochemical test, not a software algorithm that undergoes a distinct training phase in the machine learning sense. Its performance is inherent to the chemical reactions and optical detection, which are then validated against known standards and clinical samples.
9. How Ground Truth for the Training Set Was Established
Since there is no distinct "training set" in the machine learning context for this type of immunoassay, the concept of establishing ground truth for a training set is not applicable. The assay's "learning" or optimization would have occurred during its initial development and formulation, using laboratory-created spiked samples and internal validation data, much like the precision data presented. The performance characteristics described are the result of the final, developed assay.
§ 862.3650 Opiate test system.
(a)
Identification. An opiate test system is a device intended to measure any of the addictive narcotic pain-relieving opiate drugs in blood, serum, urine, gastric contents, and saliva. An opiate is any natural or synthetic drug that has morphine-like pharmocological actions. The opiates include drugs such as morphine, morphine glucoronide, heroin, codeine, nalorphine, and meperedine. Measurements obtained by this device are used in the diagnosis and treatment of opiate use or overdose and in monitoring the levels of opiate administration to ensure appropriate therapy.(b)
Classification. Class II (special controls). An opiate 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).