(113 days)
The AHDL method is an in vitro diagnostic test for the quantitative measurement of high-density lipoprotein cholesterol (HDL-C) in human serum and plasma on the Dimension® clinical chemistry system. Measurements of HDL-C are used as an aid in the diagnosis of lipid disorders (such as diabetes mellitus), various liver and renal diseases and in the assessment of risk for atherosclerosis and cardiovascular disease.
The AHDL assay measures HDL cholesterol levels directly without the need for sample pretreatment or specialized centrification steps, using a two reagent format. In the first reaction, chylpmicrons, VLDL and LDL form water soluble complexes with dextran sulfate in the presence of magnesium sulfate. These complexes are resistant to the polyethylene glycol (PEG)-modified cholesteril esterse and cholesterol oxidase that react with HDL cholesterol. In the presence of oxygen, the HDL cholesterol is oxidized to 24-cholestenone and hydrogen peroxide. The generated hydrogen peroxide then reacts with 4-aminoantipyrine and sodium N-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyaniline (HSDA) in the presence of peroxidase to form a colored dye that is measured using a bichromatic (600/700 nm) endpoint technique. The color intensity of the dye is directly proportional to the serum HDL-C concentration.
Here's an analysis of the provided text regarding the acceptance criteria and supporting study for the Dade Behring Dimension® AHDL Method:
This document is a 510(k) summary for a new version of an in vitro diagnostic (IVD) device, specifically a reagent cartridge for measuring HDL cholesterol. The study presented here is a method comparison study to demonstrate that the new device (DF48B) is substantially equivalent to a previously cleared predicate device (DF48A).
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state "acceptance criteria" in a traditional table format with pass/fail thresholds. Instead, it demonstrates substantial equivalence through a direct comparison with a predicate device and reports statistical measures of agreement.
| Performance Metric | Acceptance Criteria (Implied by Substantial Equivalence Goal) | Reported Device Performance (New Device DF48B vs. Predicate DF48A) |
|---|---|---|
| Slope | Close to 1.00 | 1.04 |
| Intercept | Close to 0 mg/dL | -3.9 mg/dL |
| Correlation Coefficient | Close to 1.00 (indicating strong linear correlation) | 1.00 |
| Intended Use | Identical to Predicate Device | Identical |
| Sample Type | Identical to Predicate Device | Identical (Human Serum or Plasma) |
| Sample Size | Identical to Predicate Device | Identical (3 uL) |
| Measuring Range | Identical to Predicate Device | Identical (3-150 mg/dL) |
Note: The "acceptance criteria" are implied by the goal of demonstrating substantial equivalence to the predicate device. The reported performance metrics (slope, intercept, correlation coefficient) are used to support this claim, showing "good analytical and clinical agreement."
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: 130 human serum samples.
- Data Provenance: The data provenance is not explicitly stated regarding country of origin. It is a retrospective study using human serum samples. The statement "using Leftover Human Specimens that are Not Individually Identifiable" from the cited FDA guidance document suggests these samples were collected previously and then used for this study.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
This type of study (method comparison for an in vitro diagnostic device) does not typically involve "experts" establishing a ground truth in the way one might for an imaging or clinical diagnosis device.
Instead, the "ground truth" for this study is implicitly the measurement obtained by the predicate device (Dimension® AHDL method, DF48A), as the goal is to show agreement of the new device (DF48B) with the established predicate. There are no external experts adjudicating the results of the predicate device.
4. Adjudication Method for the Test Set
No adjudication method is described, as it is not applicable to this type of chemical assay comparison study. The comparison is between two quantitative measurement methods.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done. This type of study is typically performed for diagnostic devices (e.g., imaging devices) where human readers interpret results, and the AI's impact on human performance is assessed. This document describes a chemical assay, so human reader involvement in the measurement itself (beyond operating the instrument) is not a relevant factor.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
Yes, a standalone performance study was inherently done. This is a standalone performance study of the device (reagent cartridge on a clinical chemistry system). The algorithm in this context refers to the chemical reaction and measurement method rather than a software algorithm making diagnostic decisions. The "performance" being evaluated is the analytical agreement of the new reagent cartridge with the predicate reagent cartridge in measuring HDL-C.
7. Type of Ground Truth Used
The "ground truth" used for this method comparison study is the quantitative measurement of HDL-C obtained from the predicate device (Dimension® AHDL method, DF48A) for the same 130 human serum samples. The study aims to demonstrate that the new device's readings are in close agreement with the predicate's readings. It is not pathology, outcomes data, or expert consensus in the typical sense.
8. Sample Size for the Training Set
The document does not mention a training set. This is expected for an in vitro diagnostic (IVD) reagent cartridge. Unlike machine learning algorithms that require training data, these chemical assays are developed and validated based on their chemical properties and analytical performance without a "training" phase on patient data.
9. How the Ground Truth for the Training Set Was Established
As there is no mention of a training set, the establishment of ground truth for a training set is not applicable.
§ 862.1475 Lipoprotein test system.
(a)
Identification. A lipoprotein test system is a device intended to measure lipoprotein in serum and plasma. Lipoprotein measurements are used in the diagnosis and treatment of lipid disorders (such as diabetes mellitus), atherosclerosis, and various liver and renal diseases.(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 § 862.9.