(28 days)
The Phosphorus assay is used for the quantitation of inorganic phosphorus in human serum, plasma, or urine. Measurements of phosphorus (inorganic) are used in the diagnosis and treatment of various disorders, including parathyroid gland and kidney diseases, and vitamin D imbalance.
Phosphorus is an in vitro diagnostic assay for the quantitative determination of inorganic phosphorus in human serum, plasma, or urine. The Phosphorus assay is a clinical chemistry assay in which the inorganic phosphorus in the sample reacts with ammonium molybdate to form a heteropolyacid complex. The absorbance is measured at 340 nm and is directly proportional to the amount of inorganic phosphorus present in the sample.
The Abbott Laboratories Phosphorus assay is an in vitro diagnostic assay for the quantitative determination of inorganic phosphorus in human serum, plasma, or urine. The device's performance was evaluated through comparative studies against the Boehringer Mannheim® Phosphorus Assay (K872494) on the Hitachi® 717 Analyzer to demonstrate substantial equivalence.
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Characteristic | Acceptance Criteria (Implied by Predicate) | Reported Device Performance (Serum) | Reported Device Performance (Urine) |
|---|---|---|---|
| Correlation Coefficient | Comparable to predicate | 0.9939 | 0.9872 |
| Slope | Comparable to predicate | 1.067 | 1.040 |
| Y-intercept | Comparable to predicate | 0.166 mg/dL | 0.970 mg/dL |
| Total %CV (Precision) | Comparable to predicate | Level 1: 1.1%, Level 2: 0.5% | Level 1: 1.6%, Level 2: 1.5% |
| Linearity (Upper Limit) | Comparable to predicate | 25.3 mg/dL | 186.2 mg/dL |
| Limit of Quantitation (Sensitivity) | Comparable to predicate | 0.10 mg/dL | Not separately reported for urine |
2. Sample Size and Data Provenance
The document does not explicitly state the sample sizes used for the comparative studies. The data provenance is not specified (e.g., country of origin, retrospective or prospective), but it can be inferred that the samples were human serum, plasma, or urine as per the intended use.
3. Number of Experts and Qualifications
Not applicable. This device is an in vitro diagnostic assay, and its performance is evaluated against a predicate device using analytical parameters rather than expert interpretation of results.
4. Adjudication Method
Not applicable. Adjudication methods are typically employed in studies involving human interpretation or subjective assessment.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
Not applicable. This is an in vitro diagnostic assay for quantitative measurement, not an AI or imaging device requiring human-in-the-loop performance evaluation.
6. Standalone Performance Study
Yes, a standalone performance study was conducted to determine the device's characteristics such as precision, linearity, and limit of quantitation. These studies were performed using the AEROSET™ System.
7. Type of Ground Truth Used
The "ground truth" for comparison was the performance characteristics of a legally marketed predicate device, the Boehringer Mannheim® Phosphorus Assay (K872494) on the Hitachi® 717 Analyzer. For precision, linearity, and sensitivity, the performance was established directly through the assays themselves, using control materials for precision and known concentrations for linearity and sensitivity.
8. Sample Size for the Training Set
Not applicable. This is not a machine learning or AI algorithm. The assay operates based on chemical reactions and photometric measurements, not a learned model from a training set.
9. How the Ground Truth for the Training Set Was Established
Not applicable. There is no training set for this type of in vitro diagnostic assay.
§ 862.1580 Phosphorus (inorganic) test system.
(a)
Identification. A phosphorus (inorganic) test system is a device intended to measure inorganic phosphorus in serum, plasma, and urine. Measurements of phosphorus (inorganic) are used in the diagnosis and treatment of various disorders, including parathyroid gland and kidney diseases, and vitamin D imbalance.(b)
Classification. Class I (general controls). 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.