(100 days)
The C-Reactive Protein assay is used for the quantitation of C-reactive protein in human serum or plasma. Measurement of C-reactive protein aids in evaluation of the amount of injury to body tissues.
C-Reactive Protein is an in vitro diagnostic assay for the quantitative determination of C-reactive protein in human serum or plasma. The C-reactive protein is a latex enhanced immunoturbidimetric assay that involves an antigen-antibody reaction between the C-reactive protein in the sample and the anti-C-reactive protein, which has been adsorbed to latex particles. The resulting agglutination is detected as an absorbance change, with the magnitude of the change being proportional to the quantity of C-reactive protein in the sample. The actual concentration is then determined by interpolation from a calibration curve prepared from calibrators of known concentration.
Here's an analysis of the provided text regarding the Abbott Laboratories C-Reactive Protein assay, focusing on acceptance criteria and the supporting study:
The provided document is a 510(k) summary for the Abbott Laboratories C-Reactive Protein assay. This type of submission focuses on demonstrating substantial equivalence to a legally marketed predicate device rather than presenting a novel device's performance against pre-defined clinical acceptance criteria. Therefore, the "acceptance criteria" discussed here are primarily focused on equivalence to the predicate device, not absolute clinical performance thresholds.
Acceptance Criteria and Reported Device Performance
The study aims to demonstrate substantial equivalence to the predicate device, Dade Behring N High Sensitivity CRP (K991385). The key metrics for this demonstration are:
| Acceptance Criteria Category | Predicate Device (Dade Behring N High Sensitivity CRP) Performance | Proposed Device (Abbott C-Reactive Protein) Performance | Meets Criteria? |
|---|---|---|---|
| Correlation Coefficient | Not explicitly stated (implied as reference standard) | 0.996 (vs. predicate on BN™ 100) | Yes |
| Slope | Not explicitly stated (implied as reference standard) | 0.97 (vs. predicate on BN™ 100) | Yes |
| Y-intercept | Not explicitly stated (implied as reference standard) | 0.07 mg/dL (vs. predicate on BN™ 100) | Yes |
| Precision (Within-run %CV) | Not explicitly stated (implied by "similar clinical results" and "similar performance characteristics") | Level 1: 1.2% - 2.0% | |
| Level 2: 1.0% - 2.3% | |||
| Level 3: 1.0% - 1.3% | Yes | ||
| Precision (Between-run %CV) | Not explicitly stated (implied by "similar clinical results" and "similar performance characteristics") | Level 1: 1.2% - 2.0% | |
| Level 2: 1.0% - 2.3% | |||
| Level 3: 1.0% - 1.3% | Yes | ||
| Precision (Between-day %CV) | Not explicitly stated (implied by "similar clinical results" and "similar performance characteristics") | Level 1: 1.2% - 2.0% | |
| Level 2: 1.0% - 2.3% | |||
| Level 3: 1.0% - 1.3% | Yes | ||
| Assay Range | Not explicitly stated (implied to be comparable) | 0.22 to 30.00 mg/dL | Yes |
| Limit of Quantitation (Sensitivity) | Not explicitly stated (implied to be comparable) | 0.216 mg/dL | Yes |
| Intended Use | Quantitative determination of C-reactive protein in human serum/plasma | Quantitative determination of C-reactive protein in human serum/plasma | Yes |
| Methodology Type | In vitro immunoassay | In vitro immunoassay | Yes |
Note: The acceptance criteria are implicitly defined by the demonstration of a strong correlation and similar precision and range to the legally marketed predicate device. The document states that the comparative performance "yielded acceptable correlation" and that the data "demonstrate that the performance... is substantially equivalent."
Study Details
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Sample size used for the test set and the data provenance:
- The document mentions "comparative performance studies" and "precision studies" using "three levels of control material." However, it does not specify the sample size for either the comparative performance (method comparison) study or the precision study.
- Data Provenance: Not explicitly stated, but typically for such in-house studies, the data would be generated in a laboratory setting (e.g., in the US, where Abbott Laboratories is located). The data type is prospective as it involves running samples on both devices to compare performance.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This question is not applicable in the context of this 510(k) submission for a quantitative diagnostic assay. The "ground truth" for a C-reactive protein assay is the actual concentration of CRP in the sample, measured by a reference method or through calibrated standards. The study compares the new device's measurements against a predicate device's measurements, where the predicate is assumed to provide accurate results.
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Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- This concept is not applicable to this type of quantitative diagnostic assay study. Adjudication methods like 2+1 or 3+1 are used in clinical studies involving interpretation of images or symptoms, where human experts reach a consensus. For a quantitative measurement device, the "truth" is typically derived from the measurement itself against a reference standard or predicate.
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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:
- No, an MRMC comparative effectiveness study was not done. This type of study is relevant for imaging devices or software that assist human interpretation. The C-Reactive Protein assay is a standalone in vitro diagnostic test for quantitative measurement, not an AI-assisted diagnostic tool requiring human interpretation.
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If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, this was a standalone performance study. The device itself is an automated in vitro diagnostic test that quantitatively measures CRP. Its performance (correlation, precision, range, sensitivity) was assessed without human interpretation of the "results" beyond the initial sample loading and result readout from the analyzer.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- The "ground truth" in this context is the measurements obtained from the legally marketed predicate device (Dade Behring N High Sensitivity CRP on the Dade Behring BN™ 100). The study's primary goal is to show agreement with this predicate, implicitly assuming the predicate provides the "truth" for comparison purposes within the scope of substantial equivalence.
- Additionally, calibrators of known concentration are used to establish the calibration curve for the proposed device, which forms part of its internal "truth" system.
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The sample size for the training set:
- The document does not mention a training set in the context of machine learning or AI models. This is a traditional in vitro diagnostic assay, not an AI-driven device.
- However, if "training set" refers to samples used for calibration, the document states the assay requires "calibration with calibrators" and that the concentration is determined by interpolation from a "calibration curve prepared from calibrators of known concentration." The number of calibrators used is not specified.
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How the ground truth for the training set was established:
- As interpreted above, if "training set" refers to calibrators, their "ground truth" (i.e., their assigned concentration) would be established by manufacturing processes, chemical assays, and traceability to reference materials/standards. The document does not provide details on how these specific calibrators' concentrations were assigned, only that they are "of known concentration."
§ 866.5270 C-reactive protein immunological test system.
(a)
Identification. A C-reactive protein immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the C-reactive protein in serum and other body fluids. Measurement of C-reactive protein aids in evaluation of the amount of injury to body tissues.(b)
Classification. Class II (performance standards).