(56 days)
For in vitro diagnostic use with the CARESIDE™ Analyzer to quantitatively measure inorganic phosphorus from anti-coagulated whole blood, plasma or serum specimens to aid in the diagnosis and treatment of various disorders, including parathyroid gland and kidney diseases, and vitamin D imbalance. It is intended for professional laboratory use: not for point of care or physician office laboratory use.
CARESIDE™ Phosphorus cartridges are used with the CARESIDE™ Analyzer to quantitatively measure phosphorus concentration in anti-coagulated whole blood, plasma or serum specimens. The CARESIDE™ Phosphorus cartridge, a single use disposable in vitro diagnostic test cartridge, aids in specimen separation and delivers a measured volume of plasma or serum to a dry film to initiate the measurement of phosphorus concentration. The film cartridge (patent pending) contains all reagents necessary to measure phosphorus concentration.
Here's an analysis of the acceptance criteria and study information for the CARESIDE™ Phosphorus device based on the provided text:
CARESIDE™ Phosphorus Device Performance Analysis
1. Acceptance Criteria and Reported Device Performance
The submission focuses on establishing substantial equivalence to a predicate device rather than defining new, explicit numerical acceptance criteria for overall performance. Instead, the acceptance is demonstrated by showing comparable or better performance across various analytical characteristics.
| Acceptance Criteria Category | CARESIDE™ Phosphorus Reported Performance | Predicate Device (Vitros PHOS DT Slides) Reported Performance |
|---|---|---|
| Detection Limit | 0.5 mg/dL | 0.5 mg/dL |
| Reportable Range | 0.5 to 15 mg/dL | 0.5 to 13 mg/dL |
| Accuracy | Mean recovery 97% | Not provided |
| Precision | Total CV, 3.5 mg/dL, 4.0% | Total CV, 4.9 mg/dL, 3.7% |
| Method Comparison | CARESIDE™ = 0.99 (Vitros PHOS DT) + 0.49, r = 1.00 (against Vitros PHOS DT) | (Implicitly, this is the reference) |
| Linearity | Linearity by mixing and by dilution yielded slope and correlation coefficients within acceptable limits. | Not provided |
| Interference | No significant interference observed at tested concentrations of: Ascorbic Acid (10 mg/dL), Bilirubin (20 mg/dL), Hemoglobin (100 mg/dL), d-Mannitol (800 mg/dL), Triglycerides (1500 mg/dL) | Not provided |
| Specimen Types | No clinically significant difference between sodium heparinized whole blood, serum, sodium heparin plasma, and EDTA plasma. | No clinically significant difference between serum, heparin plasma, or EDTA plasma. Whole blood is unsuitable. |
| Expected Values | 2.2 to 4.4 mg/dL (Central 95%) | 2.5 to 4.5 mg/dL (Central 95%) |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the sample sizes used for the various performance characteristic tests (e.g., accuracy, precision, method comparison, linearity, interference). It only lists the results.
The data provenance (country of origin, retrospective/prospective) is not specified. However, the context of a 510(k) submission to the US FDA implies that the studies were conducted to support US market approval.
3. Number of Experts Used to Establish Ground Truth and Qualifications
This device is an in vitro diagnostic (IVD) for quantitative measurement of a biochemical analyte (phosphorus). The "ground truth" for such devices is typically established through:
- Reference methods (e.g., Phosphomolybdate Reduced method mentioned in the document).
- Certified reference materials or calibrators.
- Comparison to a legally marketed predicate device, which itself would have been validated against established analytical principles and reference methods.
The document does not mention the use of human experts or their qualifications for establishing ground truth for individual test cases, as this is not typically relevant for the analytical validation of a chemical assay. The "experts" in this context are implicitly the developers and clinical chemists who ensured the assay's analytical accuracy.
4. Adjudication Method for the Test Set
Adjudication methods (e.g., 2+1, 3+1) are typically used in studies involving subjective interpretation, such as imaging diagnostics where expert readers review cases and reach a consensus. For a quantitative chemical analyzer like the CARESIDE™ Phosphorus, this type of adjudication is not applicable. The device provides a numerical result, which is then compared against established analytical standards or reference methods.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not conducted or mentioned. This type of study is relevant for diagnostic tools that involve human interpretation (e.g., radiology AI), assessing how AI assistance impacts human reader performance. The CARESIDE™ Phosphorus device is an automated chemical analyzer, not an AI-assisted diagnostic interpretation tool.
6. Standalone (Algorithm Only) Performance Study
Yes, a standalone performance study was conducted. All the reported performance characteristics (detection limit, reportable range, accuracy, precision, method comparison, linearity, interference, specimen types) represent the performance of the CARESIDE™ Phosphorus device and its integrated analyzer without human-in-the-loop interpretation. The device itself performs the measurement and calculation, making its reported performance inherently "standalone." The comparison to the predicate device essentially assesses its standalone performance against another standalone device.
7. Type of Ground Truth Used
The ground truth for this device's performance was established through:
- Reference Method Comparison: The "Reference Method" listed for both the CARESIDE™ Phosphorus and the predicate is "Phosphomolybdate Reduced," indicating that this established analytical method would have been used as a benchmark for comparison.
- Analytical Standards/Calibrators: The document mentions "lot-specific standard curve to calculate phosphorus concentration" and "Run Vitros DT II calibrators," implying the use of traceable standards and calibrators for accurate quantitative measurement.
- Predicate Device Comparison: A significant part of the safety and effectiveness claim is based on its performance in comparison to the legally marketed Vitros PHOS DT Slides. The predicate device's results would serve as a 'clinical ground truth' for the comparative effectiveness.
8. Sample Size for the Training Set
The document does not specify a separate "training set" or its sample size. For an IVD device like this, the development process typically involves:
- Method Development & Optimization: Using various samples (unknown quantity) to refine reagents, reaction conditions, and instrument parameters.
- Calibration: Using a set of samples with known concentrations to establish the relationship between the measured signal and the analyte concentration. The device uses "lot-specific standard curve" and mentions "Calibration information bar-coded on each cartridge." This implies a calibration process, which could be considered analogous to training in an AI context, but isn't typically referred to as a "training set" with specific sample numbers in IVD submissions unless it's a machine learning algorithm.
9. How the Ground Truth for the Training Set Was Established
As noted above, a distinct "training set" as understood in machine learning is not explicitly detailed. However, the "ground truth" for the calibration and development of the device would have been established through:
- Reference Methods: Using the Phosphomolybdate Reduced method or other highly accurate, established laboratory techniques to determine the true phosphorus concentration in samples used for calibration curve generation and method development.
- Certified Reference Materials: Utilizing commercially available reference materials with precisely known phosphorus concentrations.
§ 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.