(125 days)
The LIAISON® 25 OH Vitamin D TOTAL Assay uses chemiluminescent immunoassay (CLIA) technology for the quantitative determination of 25-hydroxyvitamin D and other hydroxylated vitamin D metabolites in human serum, EDTA-plasma or lithium heparin plasma to be used in the assessment of vitamin D sufficiency. Assay results should be used in conjunction with other clinical or laboratory data to assist the clinician in making individual patient management decisions in an adult population.
The LIAISON® 25 OH Vitamin D TOTAL Control Set is intended for use as assayed quality control samples to monitor the accuracy and precision of the DiaSorin LIAISON® 25 OH Vitamin D TOTAL Assay.
The LIAISON® 25 OH Vitamin D TOTAL Specimen Diluent Set may be used to dilute specimens with values greater that 150 ng/mL by the LIAISON® 25 OH Vitamin D TOTAL Assay.
The LIAISON® 25 OH Vitamin D Assay (Cat. No. 310600) is an in vitro diagnostic device consisting of reagents provided in individual compartments within a plastic container called the Reagent Integral which allows for the performance of 100 determinations.
The LIAISON® 25 OH Vitamin D TOTAL Control Set (Cat. No. 310601) consists of two controls (2 vials each) provided in a separate box.
The LIAISON® 250H Vitamin D TOTAL Specimen Diluent Set (Cat. No. 310602) may be used to dilute specimens with values greater than 150 ng/mL.
Here's an analysis of the provided text regarding the acceptance criteria and the study that proves the device meets those criteria:
The provided text describes the LIAISON® 25 OH Vitamin D TOTAL Assay, a medical device for quantitatively determining 25-hydroxyvitamin D. The document outlines its intended use, a brief description of the device components, and performance data used to demonstrate its substantial equivalence to a predicate device.
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state "acceptance criteria" for each performance metric as distinct pass/fail thresholds. Instead, it presents performance data from various studies. However, the implicit acceptance criterion for a 510(k) submission is that the device demonstrates comparable performance to a legally marketed predicate device. The "Conclusion" section explicitly states that the device is "substantially equivalent to the predicate assay."
| Performance Metric | Reported Device Performance | Implicit Acceptance Criterion (based on substantial equivalence) |
|---|---|---|
| Functional Sensitivity | 4 ng/mL | Comparable to predicate device's functional sensitivity |
| Linearity (Measuring Range) | Demonstrated linearity over 4 - 150 ng/mL. Linear regression coefficient for all sample dilutions was 0.994 and ranged from 0.988 to 0.998. | Demonstrated linearity over its stated measuring range, comparable to predicate. |
| Reproducibility/Precision: |
- Serum Samples (Repeatability) - Serum Samples (Reproducibility)
- Plasma Samples (Repeatability) - Plasma Samples (Reproducibility) | Repeatability (within-assay variability): 2.9 to 5.5% CV (mean 7.7 to 128 ng/mL)
Reproducibility (between-assay variability): 6.3 to 12.9% CV
Repeatability (within-assay variability): 3.2 to 8.1% CV (mean 5.9 to 62.7 ng/mL)
Reproducibility (between-assay variability): 6.9 to 12.7% CV | Precision (CV) comparable to the predicate device. |
| Method Comparison | LIAISON = 0.99(RIA) + 2.4, R=0.97 (compared with a commercial radioimmunoassay product) | Strong correlation (R-value) and comparable results to the predicate device. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the specific sample sizes for each performance test (e.g., how many individual serum or plasma samples were used for precision or method comparison).
- Linearity: "several serum specimens"
- Reproducibility/Precision: No specific numbers, only ranges of mean values (e.g., "over a range of mean values from 7.7 to 128 ng/mL").
- Method Comparison: No specific number for the “test set” of samples; a regression equation is provided.
Data Provenance: The document does not explicitly state the country of origin of the data or whether the studies were retrospective or prospective. It describes general laboratory performance evaluation studies.
3. Number of Experts Used to Establish Ground Truth and Qualifications
This information is not applicable to this type of device (an in vitro diagnostic immunoassay). The "ground truth" for an assay like this is typically established by reference methods or validated comparative methods, not by human experts interpreting images or complex clinical scenarios.
4. Adjudication Method for the Test Set
This is not applicable to this type of device. Adjudication methods (like 2+1 or 3+1) are common in studies where multiple human readers interpret medical images or clinical data and their interpretations need to be reconciled to establish a ground truth. For an immunoassay, the "ground truth" is derived from the result of the reference or comparative method.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
This is not applicable. An MRMC study assesses human reader performance, often in interpreting images or making clinical diagnoses, sometimes with and without AI assistance. This device is an automated immunoassay and does not involve human readers for interpretation in the same way.
6. Standalone Performance Study (Algorithm Only Without Human-in-the-Loop)
Yes, the entire performance data presented (functional sensitivity, linearity, reproducibility/precision, method comparison) represents the standalone performance of the LIAISON® 25 OH Vitamin D TOTAL Assay. This assay is designed to operate without human "in-the-loop" decision-making regarding the assay results themselves, beyond standard laboratory quality control and result reporting. The device generates quantitative values directly.
7. Type of Ground Truth Used
The ground truth for demonstrating the performance of the LIAISON® 25 OH Vitamin D TOTAL Assay was primarily established by:
- Comparative Method: For the method comparison study, a "commercial radioimmunoassay product" was used as the comparator or "ground truth" against which the new device's results were evaluated. The linear regression analysis (LIAISON = 0.99(RIA) + 2.4, R=0.97) demonstrates the correlation with this established method.
- Internal Validation/Reference Methods: For other metrics like linearity and precision, the "ground truth" is derived from rigorous internal validation studies using well-characterized samples and established laboratory protocols (e.g., CLIA EP6-A for linearity).
8. Sample Size for the Training Set
This information is not applicable or not explicitly provided. Immunoassays like this are typically developed through biochemical and analytical optimization, not by "training" a machine learning algorithm on a "training set" of data in the same way an AI/ML device would be.
9. How the Ground Truth for the Training Set Was Established
As explained in point 8, the concept of a "training set" and "ground truth" for training is generally not applicable in the context of a traditional immunoassay device. The assay's analytical characteristics are established through chemical and biological principles and then validated through performance studies.
§ 862.1825 Vitamin D test system.
(a)
Identification. A vitamin D test system is a device intended for use in clinical laboratories for the quantitative determination of 25-hydroxyvitamin D (25-OH-D) and other hydroxylated metabolites of vitamin D in serum or plasma to be used in the assessment of vitamin D sufficiency.(b)
Classification. Class II (special controls). Vitamin D test systems must comply with the following special controls:(1) Labeling in conformance with 21 CFR 809.10 and
(2) Compliance with existing standards of the National Committee on Clinical Laboratory Standards.