(28 days)
The Urea Nitrogen assay is used for the quantitation of urea nitrogen in human serum, plasma, or urine. Measurements obtained by this device are used in diagnosis and treatment of certain renal and metabolic diseases.
Urea Nitrogen is an in vitro diagnostic assay for the quantitative determination of urea nitrogen in human serum, plasma, or urine. The Urea Nitrogen assay is a clinical chemistry assay in which the the urea in the sample is hydrolyzed by urease to ammonia (NH3) and carbon dioxide (CO2). A second reaction, catalyzed by glutamate dehydrogenase (GLD), converts ammonia and a-ketoglutarate to glutamate and water with the concurrent oxidation of reduced nicotinamide adenine dinucleotide (NADH) to nicotinamide adenine dinucleotide (NAD). Two moles of NADH are oxidized for each mole of urea present. The initial rate of decrease in absorbance at 340 nm is proportional to the urea concentration in the sample.
The Abbott Laboratories Urea Nitrogen assay is an in vitro diagnostic device for the quantitative determination of urea nitrogen in human serum, plasma, or urine, used in the diagnosis and treatment of renal and metabolic diseases. It underwent a 510(k) submission to demonstrate substantial equivalence to predicate devices.
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for this device are implicitly defined by demonstrating "acceptable correlation" in comparative performance studies and acceptable precision. The reported performance is as follows:
| Performance Metric | Acceptance Criteria (Implicit) | Reported Device Performance (Serum Application) | Reported Device Performance (Urine Application) |
|---|---|---|---|
| Correlation Coefficient (vs Predicate) | Acceptable correlation | 0.9897 (vs Roche Cobas Mira Plus) | 0.9995 (vs Boehringer Mannheim) |
| Slope (vs Predicate) | Acceptable correlation | 0.963 (vs Roche Cobas Mira Plus) | 1.046 (vs Boehringer Mannheim) |
| Y-intercept (vs Predicate) | Acceptable correlation | 1.206 mg/dL (vs Roche Cobas Mira Plus) | -1.208 mg/dL (vs Boehringer Mannheim) |
| Total %CV (Level 1) | Acceptable precision | 4.9% | 3.0% |
| Total %CV (Level 2) | Acceptable precision | 3.9% | 3.3% |
| Linearity | Up to 120 mg/dL | Not specified for urine independently | |
| Limit of Quantitation (Sensitivity) | 1.8 mg/dL | Not specified for urine independently |
2. Sample Size Used for the Test Set and Data Provenance
The document does not specify the exact sample size for the test set used in the comparative performance studies. It only states that "Comparative performance studies were conducted" and presents summary statistics (correlation coefficient, slope, Y-intercept).
The data provenance is not explicitly stated in terms of country of origin or whether it was retrospective or prospective. However, given it's a 510(k) submission for a clinical chemistry assay, the data would typically be derived from laboratory tests, and the intent is for prospective clinical use.
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 where the "ground truth" is established by the comparative performance against legally marketed predicate devices using objective measurements, not by expert interpretation of images or other subjective assessments.
4. Adjudication Method for the Test Set
Not applicable. Adjudication methods (like 2+1, 3+1) are typically used in studies involving human interpretation or subjective assessment to resolve discrepancies in expert opinions. This device's performance is assessed through quantitative comparisons with predicate devices.
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 a standalone in vitro diagnostic assay, not an AI-assisted diagnostic tool designed to aid human readers. Therefore, an MRMC study and
the concept of human reader improvement with AI assistance do not apply.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance study was done. The entire submission describes the performance of the Abbott Urea Nitrogen assay itself (the "algorithm only" in the context of an IVD) without human-in-the-loop performance modifications or assistance. Its performance characteristics (correlation, precision, linearity, sensitivity) were measured intrinsically and compared to predicate devices.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
For the comparative performance studies, the "ground truth" was established by the results obtained from the legally marketed predicate devices:
- Roche Cobas Mira Plus Automated Chemistry System Urea Nitrogen assay (K954000) for the serum application.
- Boehringer Mannheim Urea Nitrogen assay on the Hitachi 717 Analyzer (K771923) for the urine application.
These predicate devices are assumed to provide accurate measurements of urea nitrogen, serving as the reference for determining the substantial equivalence of the new device.
8. The Sample Size for the Training Set
Not applicable. This is a traditional in vitro diagnostic assay, not a machine learning or AI-based device that requires a distinct "training set" in the conventional sense. The development of such an assay involves reagent formulation, instrument calibration, and optimization based on chemical principles and experimental data, rather than training on a dataset.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no specific "training set" in the context of this traditional IVD development. The "ground truth" in the development of such assays is based on established analytical chemistry principles, reference methods, and quality control materials.
§ 862.1770 Urea nitrogen test system.
(a)
Identification. A urea nitrogen test system is a device intended to measure urea nitrogen (an end-product of nitrogen metabolism) in whole blood, serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of certain renal and metabolic diseases.(b)
Classification. Class II.