(108 days)
The S-Test C-Reactive Protein Reagent Cartridge is intended for the quantitative determination of C-reactive protein concentration in serum or heparin plasma using the S40 Clinical Analyzer. Measurement of C-reactive protein aids in evaluation of the amount of injury to body tissues. This test is intended for use in clinical laboratories or physician office laboratories. For in vitro diagnostic use only.
The S-Test C-Reactive Protein (CRP) reagent cartridge, used with the S40 Clinical Analyzer, is intended for quantitative in vitro diagnostic determination of CRP in serum or heparin plasma based on a photometric test measuring the agglutination that results when an antigen-antibody reaction occurs between CRP in the sample and anti-CRP mouse monoclonal antibody-coated latex.
Here's a breakdown of the acceptance criteria and study information for the S-Test CRP Reagent cartridge, based on the provided text:
Acceptance Criteria and Device Performance
| Acceptance Criteria Category | Specific Metric | Reported Device Performance |
|---|---|---|
| Precision | Within-run CV (Clinical Lab) | Ranged from 1.1% to 3.0% |
| Total CV (Clinical Lab) | Ranged from 2.3% to 4.3% | |
| Within-run CV (Physician Office Lab - POL) | Ranged from 1.0% to 7.5% | |
| Total CV (Physician Office Lab - POL) | Ranged from 1.5% to 7.5% | |
| Accuracy | Correlation coefficient (R-value) | 0.995 (for 95 samples with CRP values 5-91 mg/L) |
| Standard error estimate | 2.1 (for 95 samples with CRP values 5-91 mg/L) | |
| Confidence interval slope | 0.961 to 1.004 (for 95 samples with CRP values 5-91 mg/L) | |
| Confidence interval intercept | 0.4 to 1.6 (for 95 samples with CRP values 5-91 mg/L) | |
| Correlation coefficient (POL sites) | 0.997 to 0.998 | |
| Standard error estimate (POL sites) | 1.5 to 1.6 | |
| Confidence interval slopes (POL sites) | 0.934 to 0.986 | |
| Confidence interval intercepts (POL sites) | -0.1 to 2.1 | |
| Sensitivity | Detection Limit | 2 mg/L |
| Matrix Comparison | Statistical significance (Serum vs. Heparin Plasma) | Paired t-test for means: t-Statistic = 0.13, t-Critical value 2.08 at α = 0.05, not statistically significant. This indicates no significant difference between serum and heparin plasma samples for CRP determination over a range of 7 to 96 mg/L. |
Study Information
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Sample size used for the test set and the data provenance:
- Clinical Lab Accuracy Study: 95 samples with CRP values ranging from 5 to 91 mg/L.
- POL Site Accuracy Studies: The exact number of samples is not specified for each POL site, but it states "patient correlation studies at three separate POL sites."
- Precision Studies: Not explicitly stated as a "test set" in the same way as accuracy, but samples were tested at "three CRP levels for 24 days" in the clinical lab and "at three separate Physician Office Laboratory (POL) sites and in-house over five days."
- Serum vs. Plasma Study: 22 paired samples (serum and heparin plasma from the same patients).
- Data Provenance: Not explicitly stated (e.g., country of origin, retrospective/prospective). However, the mention of "in-house" and "three separate Physician Office Laboratory (POL) sites" suggests data collected through internal R&D and clinical settings, likely prospective for the specific studies.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This device is an in-vitro diagnostic (IVD) for quantitative measurement, not an imaging or diagnostic device requiring human expert interpretation for "ground truth." The "ground truth" for its performance evaluation comes from a comparative method (predicate device or established clinical method) rather than human experts.
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Adjudication method for the test set:
- Not applicable as the "ground truth" is established by a comparative method, not human interpretation requiring adjudication.
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If a multi-reader multi-case (MRMC) comparative effectiveness study was done:
- No, an MRMC study was not done. This type of study is relevant for devices that involve human interpretation of images or other data, where the AI assists the human reader. The S-Test CRP Reagent cartridge is an automated quantitative assay.
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If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
- Yes, the performance data presented (precision, accuracy, sensitivity) are for the standalone algorithm/device (S-Test CRP reagent cartridge on the S40 Clinical Analyzer) measuring CRP levels. There is no human interpretation component in the measurement process itself.
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The type of ground truth used:
- The "ground truth" for the accuracy studies was established by a comparative method (likely either the Olympus AU640 Clinical Chemistry Analyzer CRP Latex Reagent, which is the predicate for the system, or another clinically accepted method). The text states: "...assayed on the S40 Clinical Analyzer using S-Test CRP (y) and a comparative method (x)."
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The sample size for the training set:
- The document describes performance data for the final device (test set), not the training set used during development. Therefore, the sample size for the training set is not provided in this summary.
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How the ground truth for the training set was established:
- Since the training set size is not provided, the method for establishing its ground truth is also not specified in this document. Assuming a typical IVD development process, the training data would also likely have been compared against a reference or comparative method.
§ 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).