(59 days)
CR-E reagent, when used in conjunction with SYNCHRON® Systems, UniCel® DxC Systems and SYNCHRON® Systems AQUA CAL 1 and 2 and SYNCHRON CX® Calibrator Level 1 and 2, is intended for the quantitative determination of creatinine (CR-E) concentration in human serum, plasma or urine (urine is not available on the SYNCHRON CX® PRO Systems). 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.
CR-E reagent is used to measure the creatinine concentration by an enzymatic method. This enzymatic creatinine method utilizes a multi-step approach ending with a photometric end-point reaction. The SYNCHRON Enzymatic Creatinine (CR-E) Reagent is designed for optimal performance on the SYNCHRON LX®, UniCel® DxC 600/800, and SYNCHRON CX® PRO Clinical Systems. The reagent kit contains two 200-test cartridges that are packaged separately from the associated calibrator.
The provided [K091742](https://510k.innolitics.com/search/K091742) document describes the SYNCHRON® Systems Enzymatic Creatinine (CR-E) Reagent. The acceptance criteria and the study that proves the device meets them are summarized below.
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state pre-defined acceptance criteria in terms of numerical thresholds for slope, intercept, R-value, or %C.V. for its performance metrics. Instead, it presents the results of its performance studies (method comparison and precision studies) which are then compared to a legally marketed predicate device (SYNCHRON Systems Creatinine (CR-S) Reagent) to demonstrate substantial equivalence. For the purpose of this response, "reported device performance" refers to the values obtained in the studies.
| Performance Metric | Acceptance Criteria (Implied/Compared to Predicate) | Reported Device Performance (CR-E Reagent) |
|---|---|---|
| Method Comparison (Serum) | ||
| Slope (vs. Predicate) | Close to 1.0 (indicating proportionality) | CX7 PRO Platform: 0.997 |
| Intercept (vs. Predicate) | Close to 0.0 (indicating no systematic bias) | CX7 PRO Platform: -0.002 |
| R (Correlation Coefficient) | Close to 1.0 (indicating strong correlation) | CX7 PRO Platform: 1.000 |
| Slope (vs. Predicate) | Close to 1.0 (indicating proportionality) | DxC800 Platform: 0.991 |
| Intercept (vs. Predicate) | Close to 0.0 (indicating no systematic bias) | DxC800 Platform: 0.012 |
| R (Correlation Coefficient) | Close to 1.0 (indicating strong correlation) | DxC800 Platform: 1.000 |
| Method Comparison (Urine) | ||
| Slope (vs. Predicate) | Close to 1.0 (indicating proportionality) | DxC800 Platform: 0.988 |
| Intercept (vs. Predicate) | Close to 0.0 (indicating no systematic bias) | DxC800 Platform: -3.096 |
| R (Correlation Coefficient) | Close to 1.0 (indicating strong correlation) | DxC800 Platform: 0.998 |
| Precision (Within-Run & Total Imprecision) | ||
| %C.V. (Coefficient of Variation) | Low values, consistent with precise measurement for clinical use (compared to typical lab practice and predicate's performance) | CX7 PRO: |
| Within-Run: 0.3% - 1.4% | ||
| Total: 0.5% - 1.5% | ||
| DxC800 (Serum): | ||
| Within-Run: 0.3% - 2.1% | ||
| Total: 0.7% - 2.5% | ||
| DxC800 (Urine): | ||
| Within-Run: 0.4% - 0.5% | ||
| Total: 1.0% |
2. Sample Sizes Used for the Test Set and Data Provenance
-
Method Comparison Studies:
- Serum (CX7 PRO Platform): N = 78 samples
- Serum (DxC800 Platform): N = 80 samples
- Urine (DxC800 Platform): N = 66 samples
- Data Provenance: The document does not explicitly state the country of origin or whether the data was retrospective or prospective. Given it is a premarket submission for a medical device to the FDA, it is highly likely these were prospective studies conducted to demonstrate equivalence for regulatory approval.
-
Precision Studies:
- CX7 PRO Platform: N = 80 for each of the 4 sample levels/pools (Level 1, Level 2, Level 3, Human Pool) for both within-run and total imprecision.
- DxC800 Platform (Serum): N = 80 for each of the 4 sample levels/pools for both within-run and total imprecision.
- DxC800 Platform (Urine): N = 80 for each of the 2 urine sample levels/pools for both within-run and total imprecision.
- Data Provenance: The document does not explicitly state the country of origin or whether the data was retrospective or prospective. It is implied these were prospective studies.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of those Experts
The ground truth in this submission is established through comparison to a predicate device (SYNCHRON Systems Creatinine (CR-S) Reagent), which is a legally marketed device often used as a reference method in clinical laboratories. This is not a ground truth established by human experts, but rather by an accepted analytical method. Therefore, the concept of "experts" as in radiologists reading images is not applicable here.
4. Adjudication Method for the Test Set
Not applicable. The ground truth is established by a predicate analytical method, not human interpretation that would require an adjudication method.
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 relevant for diagnostic imaging interpretation where human readers (e.g., radiologists) evaluate cases. This submission concerns an in vitro diagnostic reagent for quantitative chemical analysis, which relies on instrument readings rather than human interpretation.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, this entire study represents a standalone performance evaluation of the SYNCHRON® Systems Enzymatic Creatinine (CR-E) Reagent. The device (reagent used on automated analyzers) produces quantitative creatinine measurements directly, without human interpretation of results as part of its primary function. The data presented are direct outputs from the synchronized clinical systems.
7. The Type of Ground Truth Used
The type of ground truth used for the method comparison studies is comparison to a legally marketed predicate device's performance, specifically the SYNCHRON Systems Creatinine (CR-S) Reagent. This is implicitly considered a well-established and accepted method for creatinine determination. For precision, the ground truth is statistical assessment of reproducibility around the measured mean.
8. The Sample Size for the Training Set
The document does not explicitly mention a "training set" in the context of machine learning or AI. This product is a chemical reagent for an enzymatic assay, not an AI or machine learning algorithm that requires a separate training phase with a distinct dataset. Clinical chemistry assays often involve calibration, internal quality control, and validation studies but do not typically concept of a "training set" for an algorithm. The reported studies are for validation/testing of the device's performance.
9. How the Ground Truth for the Training Set Was Established
As noted above, the concept of a "training set" is not applicable to this type of device. The performance validation studies (method comparison and precision) demonstrate the accuracy and reliability of the CR-E reagent against a predicate method and statistical standards for precision.
§ 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.