(49 days)
Gentian Cystatin C Immunoassay is an in-vitro diagnostic test for quantitative determination of cystatin c in human serum and plasma. The measurement of cystatin c is used in the diagnosis and treatment of renal diseases.
The instruments that can be used with the assay are: The Beckman Coulter™ Synchron® and UniCel® Systems
The Gentian cystatin C Immunoassay is a particle enhanced turbidimetric immunoassay (PETIA). The immunoparticles are made from activated polystyrene microspheres to which avian anti-human cystatin C antibodies are covalently attached. The immunoparticles and cystatin C form aggregations that change the absorbance signal, depending on the amount of cystatin C present. Measurements obtained by this device are used for the determination of Cystatin C in human serum and plasma. The Gentian cystatin C assay is calibrated with human Cystatin C calibrators. Cystatin C controls are assayed for the verification of the accuracy and precision of the Gentian cystatin C immunoassay.
Here's a breakdown of the acceptance criteria and study details for the Gentian Cystatin C Immunoassay, based on your provided text:
1. Table of Acceptance Criteria and Reported Device Performance
For Comparison Between Synchron and Architect (Predicate Device)
| Sample type | Regression Parameter | Acceptance Criteria | Coefficient | Confidence Interval |
|---|---|---|---|---|
| Serum N=47 | Slope | 1.0 ± 0.075 | 0.95 | 0.93 - 0.97 |
| Intercept (mg/L) | 0 ± 0.20 | 0.17 | 0.13 - 0.22 |
All reported coefficients and their confidence intervals fall within the defined acceptance criteria, demonstrating substantial equivalence between the Synchron and the Architect applications.
For Instrument Variation Between Synchron LX20 and UniCel DxC
| Analysis | Parameter | Acceptance Criteria | Coefficient | Confidence Interval |
|---|---|---|---|---|
| Passing-Bablock N=50 | Slope | 1 ± 0.05 | 0.97 | 0.95-1.00 |
| Intercept (mg/L) | 0 ± 0.10 | 0.03 | -0.01-0.06 | |
| Bland-Altman N=50 | Bias (%) | 0 ± 5 | -1.2 | -2.4-0.0 |
| 95% limit of agreement (%) | 0 ± 10 | -9.5 to 7.1 | -11.6 - -7.4 | |
| 5.0 - 9.2 |
All reported coefficients and their confidence intervals fall within the defined acceptance criteria, demonstrating substantial equivalence between the Synchron LX20 and UniCel DxC instruments.
2. Sample Sizes and Data Provenance
- Test Set for Synchron vs. Architect Comparison:
- Sample Size: N=47 serum samples.
- Data Provenance: Not explicitly stated, but clinical samples are implied for method comparison. The country of origin is not specified. It is likely retrospective as part of a method validation study.
- Test Set for Instrument Variation (Synchron LX20 vs. UniCel DxC):
- Sample Size: N=50 samples for both Passing-Bablock and Bland-Altman analyses.
- Data Provenance: Not explicitly stated, but clinical samples are implied for method comparison. The country of origin is not specified. It is likely retrospective as part of a method validation study.
3. Number of Experts and Qualifications for Ground Truth
- Not applicable as this is an in-vitro diagnostic device for quantitative measurement, not an imaging device requiring expert interpretation. The "ground truth" here is the measurement from a reference or predicate device/method.
4. Adjudication Method
- Not applicable for this type of quantitative assay comparison. The assessment is based on statistical comparison of numerical results, not subjective interpretation.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- Not applicable. This is an in-vitro diagnostic device, not an AI-assisted diagnostic tool for human readers.
6. Standalone (Algorithm Only Without Human-in-the-loop) Performance
- Yes, the performance criteria (e.g., slope, intercept, bias) are for the device's output (measurements of Cystatin C) in comparison to another instrument or predicate device. This is inherently a standalone performance assessment of the instrument/assay itself, without human interpretation as part of the core measurement.
7. Type of Ground Truth Used
- Reference Method/Predicate Device: The ground truth for the comparison study between Synchron and Architect was the measurements obtained from the Gentian Cystatin C Immunoassay on the Abbott Architect c8000 instrument (K071388), which is the predicate device.
- Instrument Equivalence: For the instrument variation study between Synchron LX20 and UniCel DxC, the "ground truth" (or reference for comparison) for each instrument's performance was the result from the other instrument, to demonstrate their equivalence. This is a head-to-head comparison rather than comparison to an absolute gold standard.
8. Sample Size for the Training Set
- Not explicitly stated or applicable as described. Clinical chemistry assays typically don't have "training sets" in the same way machine learning algorithms do, but rather undergo calibration using calibrators and quality control materials. The assay itself is a measurement system, not a learning algorithm that generates predictions from input features.
9. How Ground Truth for the Training Set Was Established
- Not explicitly stated or applicable as described for a traditional "training set" in a machine learning context. The assay is calibrated using human Cystatin C calibrators. The establishment of the "ground truth" for these calibrators would involve a traceable reference method and standards, but details are not provided in this summary.
§ 862.1225 Creatinine test system.
(a)
Identification. A creatinine test system is a device intended to measure creatinine levels in plasma and urine. Creatinine measurements are used in the diagnosis and treatment of renal diseases, in monitoring renal dialysis, and as a calculation basis for measuring other urine analytes.(b)
Classification. Class II.