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The Cystatin C assay is an in vitro diagnostic test used in the quantitative immunoturbidimetric determination of cystatin C in human serum and plasma on the Alinity c system.

Measurement of cystatin C aids in the diagnosis and treatment of renal diseases.

For laboratory professional use only.

The Cystatin C assay is an automated clinical chemistry assay.

Cystatin C is a particle-enhanced turbidimetric immunoassay (PETIA) developed to accurately and reproducibly measure cystatin C levels in serum and plasma. Latex particles coated with anti-human cystatin C antibody agglutinate when mixed with sample containing human cystatin C. The change in absorbance due to agglutination of the reaction mixture is proportional to the quantity of human cystatin C in the sample.

The provided text is a 510(k) clearance letter for an in vitro diagnostic test (Cystatin C assay), not an AI/ML-driven medical device. Therefore, the information requested for AI/ML device studies (such as MRMC studies, expert adjudication, training set ground truth, etc.) is not applicable to this document.

However, I can extract and present the performance acceptance criteria and reported device performance from the provided document, even though they relate to a traditional laboratory assay rather than an AI/ML model.

Here's an interpretation based on the provided text for a traditional in vitro diagnostic device:

Based on the provided FDA 510(k) clearance letter for the Cystatin C Test System, the device is a quantitative immunoturbidimetric assay for the determination of cystatin C in human serum and plasma. The performance of this device was demonstrated through various nonclinical studies.

1. Table of Acceptance Criteria and Reported Device Performance

For in vitro diagnostic tests like the Cystatin C assay, "acceptance criteria" are typically defined by ranges or thresholds for performance characteristics such as precision, accuracy (bias), linearity, and limits of detection. The document describes the reported performance measured during the studies, and implicitly, these figures met the internal acceptance criteria set by the manufacturer (and approved by the FDA for clearance).

Here's a summary of the reported device performance:

Study Details (Relevant to IVD, not AI/ML)

The following points are addressed as much as possible for an in vitro diagnostic device, noting where the requested AI/ML specific information is not applicable.

2. Sample sizes used for the test set and the data provenance:

   • Precision/Reproducibility:
     • Within-Laboratory Precision: 80 replicates per sample/control (2 replicates/day for 20 days) for 2 controls and 4 human serum panels.
     • Reproducibility: 240 replicates per sample/control (4 replicates, twice/day for 5 days at 3 sites) for 2 controls and 3 human serum panels.
   • Accuracy (Bias): Not specified as a separate sample size, but involved testing across 2 reagent lots and 2 calibrator lots.
   • Linearity: Not specified as a number of distinct samples, but assessed over a range of concentrations.
   • Lower Limits of Measurement (LoB, LoD, LoQ): ≥ 60 replicates of zero-analyte samples for LoB, and ≥ 60 replicates of low-analyte level samples for LoD/LoQ.
   • Analytical Specificity (Interference): Each substance tested at 2 analyte levels.
   • Method Comparison: 161 serum samples.
   • Matrix Comparison: Not specified as a specific number, but evaluated across various tube types.
   • High Dose Hook: Not specified as a specific number of samples, but tested up to 40.00 mg/L.
   • Expected Values (Reference Interval): 250 apparently healthy individuals (105 females, 145 males) with eGFR > 80, aged 18 to 69 years.

   Data Provenance: The document does not explicitly state the country of origin for the clinical samples. The studies are described as "nonclinical performance" studies, meaning they evaluate the analytical performance of the assay itself, rather than diagnostic accuracy in a clinical setting with patient outcomes. These are typically prospective studies conducted in a controlled lab environment.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

   • Not applicable for this in vitro diagnostic device. Ground truth for analytical performance studies of IVDs is established by the known concentration of analytes in reference materials, calibrators, and characterized control samples, or by comparison to a well-established reference or predicate method. It does not involve expert readers or their consensus.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:

   • Not applicable for this in vitro diagnostic device. Adjudication methods are relevant for subjective image-based assessments or clinical diagnoses where human interpretation varies. This product is a quantitative chemical assay.

5. 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:

   • Not applicable for this in vitro diagnostic device. MRMC studies are for evaluating the impact of AI on human reader performance, typically in radiology or similar interpretive fields. This device performs automated measurements.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

   • Analogous concept applies. The performance data presented (precision, accuracy, linearity, limits of detection, etc.) are the standalone performance of the assay on the Alinity c system. It demonstrates the device's ability to measure Cystatin C without human interpretation of the analytical signal.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

   • For the analytical performance studies, the ground truth was established by:
     • Certified reference materials: Specifically, ERM-DA471/IFCC for assay standardization and accuracy validation.
     • Preparation of known concentrations: Through spiking or dilution of samples to evaluate linearity and limits of measurement.
     • Comparison to a validated comparator assay: For method comparison (Cystatin C on Alinity c vs a Comparator Cystatin C assay).
     • Characterized control materials: For precision and reproducibility studies.
     • Established healthy population studies: For determining the reference interval.

8. The sample size for the training set:

   • Not applicable in the AI/ML sense. This is a traditional chemical assay, not an AI/ML model that undergoes a "training" phase with data. The assay's parameters are developed through conventional analytical chemistry principles and validated through the nonclinical performance studies detailed.
   • Development would involve formulation and optimization studies, but not "training data" in the AI sense.

9. How the ground truth for the training set was established:

   • Not applicable for this in vitro diagnostic device. As noted above, there is no "training set" in the AI/ML context for a traditional immunoturbidimetric assay. The "ground truth" for developing such an assay would be based on fundamental chemical principles, known concentrations of analytes, and established analytical chemistry standards.

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The ADVIA® Chemistry Cystatin C 2 (CYSC 2) assay is for the in vitro diagnostic use in the quantitative determination of cystatin C in human serum and plasma (lithium heparin, potassium EDTA) on ADVIA Chemistry systems. Measurement of cystatin C aids in the diagnosis and treatment of renal disease.

The ADVIA Cystatin C_2 assay (CYSC_2) is an in vitro diagnostics kit containing reagents for the quantitative determination of cystatin C in human serum and plasma by means of particle-enhanced turbidimetry using the ADVIA Chemistry Systems. Used in conjunction with other clinical and laboratory findings, ADVIA Chemistry Cystatin C 2 measurements are used as an aid in the diagnosis and treatment of renal diseases.

The ADVIA Chemistry Cystatin C 2 latex reagent is a suspension of uniform latex particles coated with anti-cystatin-C antibody. When serum or plasma containing cystatin C is mixed with the latex reagent, agglutination takes place resulting in an increase in turbidity. This turbidity is measured at 571 and 805 nm. The cystatin C concentration in serum or plasma is determined from a calibration curve that is generated with the calibrators.

The provided text describes the 510(k) premarket notification for the ADVIA Chemistry Cystatin C 2 Assay (CYSC 2). This is an in vitro diagnostic (IVD) device, not an AI/ML software device. Therefore, many of the requested criteria related to AI/ML device performance (e.g., human-in-the-loop, training set, ground truth experts) are not applicable.

However, I can extract and present the relevant acceptance criteria and study information for this IVD device based on the provided text.

Here's the breakdown of the acceptance criteria and the study proving the device meets them, focusing on the appropriate metrics for an IVD assay:

Acceptance Criteria and Device Performance for ADVIA Chemistry Cystatin C 2 Assay (CYSC 2)

Note: This device is an In Vitro Diagnostic (IVD) assay designed to quantitatively measure Cystatin C in human serum and plasma. Its performance is evaluated through analytical studies, not typically through human-in-the-loop or AI-related metrics. Thus, many of the requested fields (e.g., number of experts, adjudication, MRMC study, standalone AI performance, training set details) are not applicable to this type of device.

1. Table of Acceptance Criteria and Reported Device Performance

2. Sample Size and Data Provenance for Test Set

• Sample Size for Method Comparison: 158 frozen human serum samples.
• Data Provenance: Not explicitly stated regarding country of origin or whether samples were prospective/retrospective. The samples were "frozen human serum samples." The predicate device (N Latex Cystatin C) is from Siemens as well, suggesting internal or collaboration data. The healthy samples for expected values were from a "normal range study, performed by Siemens."

3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications

Not Applicable.
For an IVD assay measuring a quantitative analyte like Cystatin C, the "ground truth" is established by direct measurement using a reference method or by comparing analytical performance to a legally marketed predicate device. This does not involve human expert interpretation of images or other subjective data.

4. Adjudication Method for the Test Set

Not Applicable.
As stated above, this is an IVD assay for quantitative measurement, not an AI/ML device relying on human interpretation and adjudication.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

Not Applicable.
This is an IVD assay, not an AI/ML diagnostic aid for human readers. Its performance is evaluated through analytical studies, not comparative effectiveness of human readers.

6. Standalone (i.e. algorithm only without human-in-the-loop performance) Performance

The listed performance characteristics are the standalone performance of the assay. The device itself (reagents, calibrators, and system) performs the measurement. There is no "human-in-the-loop" once the sample is loaded and the assay run on the instrument, other than for initial setup, quality control, and result interpretation by a clinician.

7. Type of Ground Truth Used

For the method comparison study, the "ground truth" or reference was the N Latex Cystatin C assay (K171072), the predicate device.
For other analytical performance characteristics (precision, linearity, detection capability, interference), the "ground truth" is inherent to the statistical and analytical methods used (e.g., gravimetric dilutions for linearity, certified reference materials for traceability, statistical analysis of replicates for precision/detection limits).
For expected values, the "ground truth" was established by measuring 208 apparently healthy samples (i.e., a healthy population study).

8. Sample Size for the Training Set

Not Applicable.
This is a laboratory diagnostic assay, not a machine learning algorithm that requires a "training set" in the computational sense. The "training" of the assay refers to its development and optimization through extensive laboratory testing and validation, not a data-driven training process.

9. How the Ground Truth for the Training Set was Established

Not Applicable.
There is no "training set" ground truth in the context of an IVD assay as understood for AI/ML devices. The "ground truth" for developing and validating the assay is primarily defined by established metrological principles, analytical chemistry standards, and comparison to recognized reference methods or predicate devices.

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N Latex Cystatin C: N Latex Cystatin C is an in vitro diagnostics kit containing reagents for the quantitative determination of cystatin C in human serum and lithium-heparinized plasma by means of particle-enhanced immunonephelometry using the BN Systems. Cystatin C measurements are used in the diagnosis and treatment of renal diseases. N Protein Standard UY: N Protein Standard UY is used for preparing reference curves for the immunonephelometric determination of a1microglobulin and Cystatin C using the BN Systems.

The N Latex Cystatin C is an in vitro diagnostics kit containing reagents for the quantitative determination of cystatin C in human serum and lithium heparinized plasma by means of particle-enhanced immunonephelometry using the BN II and BN ProSpec® Systems. Used in conjunction with other clinical and laboratory findings, N Latex Cystatin C measurements are used as an aid in the diagnosis and treatment of renal diseases. Used in conjunction with the assay reagents, N Protein Standard UY is for use in the establishment of reference curves for the determination of cystatin C on the BN II and BN ProSpec Systems. N Cystatin C Control 1 and 2 are included with N Latex Cystatin C kit and are for use as assayed accuracy controls and precision controls in the determination of cystatin C by immunonephelometry with the BN II and BN ProSpec Systems. The N Latex Cystatin C test system is based upon the principles of particle-enhanced immunonephelometry. Polystyrene particles coated with specific antibodies to human cystatin C are aggregated when mixed with samples containing human cystatin C. These aggregates scatter a beam of light passed through the sample. The intensity of the scattered light is proportional to the concentration of the respective protein in the sample. The result is evaluated by comparison with a standard of known concentration.

Acceptance Criteria and Device Performance for N Latex Cystatin C

This document summarizes the acceptance criteria and performance study results for the N Latex Cystatin C device, as described in the provided FDA 510(k) summary (K171072).

1. Table of Acceptance Criteria and Reported Device Performance

The provided document details performance studies but does not explicitly define a "table of acceptance criteria". Instead, it describes established methodologies and states that "Results met the pre-established acceptance criteria." for the method comparison study. Based on the reported data, the following can be inferred as performance metrics that met the sponsor's internal acceptance criteria for substantial equivalence:

• CysC Control 1: Repeatability CV 1.78%, Within-device/lab CV 1.78%
• CysC Control 2: Repeatability CV 1.00%, Within-device/lab CV 1.01%
• Serum Pool 1: Repeatability CV 3.85%, Within-device/lab CV 3.85%
• Serum Pool 2: Repeatability CV 1.39%, Within-device/lab CV 1.41%
• Serum Pool 3: Repeatability CV 1.62%, Within-device/lab CV 1.62%
• Plasma Pool 1: Repeatability CV 2.38%, Within-device/lab CV 2.65%
• Plasma Pool 2: Repeatability CV 2.09%, Within-device/lab CV 2.09%
• Plasma Pool 3: Repeatability CV 1.07%, Within-device/lab CV 1.26%

BN II:

• CysC Control 1: Repeatability CV 1.93%, Within-device/lab CV 2.24%
• CysC Control 2: Repeatability CV 1.42%, Within-device/lab CV 1.54%
• Serum Pool 1: Repeatability CV 2.54%, Within-device/lab CV 2.62%
• Serum Pool 2: Repeatability CV 1.34%, Within-device/lab CV 1.55%
• Serum Pool 3: Repeatability CV 1.69%, Within-device/lab CV 1.80%
• Plasma Pool 1: Repeatability CV 2.59%, Within-device/lab CV 2.59%
• Plasma Pool 2: Repeatability CV 1.62%, Within-device/lab CV 1.75%
• Plasma Pool 3: Repeatability CV 1.98%, Within-device/lab CV 2.42% |
  | Measuring Range (Linearity) | Acceptable linearity over the specified range. | Demonstrated linearity over the range of 0.27 to 10.3 mg/L. |
  | Limit of Quantitation (LoQ) | LoQ at a specified %CV (e.g.,

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Tina-quant Cystatin Gen.2 is an in vitro test for the quantitative determination of cystatin C in human serum and plasma on Roche/Hitachi cobas c systems. Cystatin C measurements are used as an aid in the diagnosis and treatment of renal diseases.

The Roche Tina-quant Cystatin C Gen.2 assay provides quantitative measurement of the cystatin C that is present in human serum and plasma. The reagents are packaged in a cassette with two bottles labeled with their instrument positioning, R1 (Reagent 1) and R2 (Reagent 2).

R1 contains a solution of polymers in MOPS-buffered saline with preservative and stabilizers. R2 is latex particles coated with anti-cystatin C antibodies (rabbit) in glycine buffer with preservatives and stabilizers.

Human cystatin C agglutinates with the antibody coated latex particles. The aggregate is determined turbidimetrically.

The provided text describes a 510(k) premarket notification for a modified in vitro diagnostic device, "Tina-quant Cystatin C Gen.2". The modifications primarily involve updated labeling information rather than changes to the device itself. Therefore, the study details are focused on validating these labeling changes.

Here's an analysis based on the provided document:

1. A table of acceptance criteria and the reported device performance

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

• Sample Stability: Human serum and plasma patient samples were adjusted with cystatin C. The exact number of samples is not explicitly stated, but it mentions "patient samples" and that "These samples are split into two sets". The text does not specify the country of origin or whether the data was retrospective or prospective, but it implies prospective testing for stability.
• High dose hook-effect: A human serum pool was used, from which an 18-step dilution series was prepared. The exact volume or number of individual samples within the pool is not specified. Data provenance is not given.
• HARA interference: "Internal testing was done at Roche to confirm the customer results." The number of samples tested internally and the provenance of customer data are not detailed.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

Not applicable. This device is an in vitro diagnostic (assay for a biomarker), not an imaging or diagnostic device requiring expert interpretation of results for ground truth. Ground truth for an assay is typically established through reference methods or spiked samples with known concentrations.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Not applicable. Adjudication methods like 2+1 or 3+1 are typically used in clinical trials or studies where subjective interpretations (e.g., image readings) are being evaluated. For an IVD, the results are quantitative measures.

5. 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

Not applicable. This study is for a laboratory assay, not an AI-assisted diagnostic tool for human readers.

6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done

This refers to the performance of the analytical device itself. The studies described for sample stability, hook effect, and HARA interference were standalone evaluations of the assay's performance characteristics.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

• Sample Stability: The ground truth for sample stability was the result of the fresh sample at time zero, which is considered the baseline and implicitly the "true" concentration at that point.
• High dose hook-effect: The ground truth was the "known concentration" obtained from preparing a dilution series from a concentrated serum pool.
• HARA interference: The ground truth was based on confirming "falsely elevated results" observed in patient samples and corroborated by peer-reviewed literature.

8. The sample size for the training set

Not applicable. This device is an in vitro diagnostic reagent kit, not a machine learning or AI algorithm that requires a training set. The "training set" concept does not apply here.

9. How the ground truth for the training set was established

Not applicable, as there is no training set for this type of device.

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The Tina-quant Cystatin C Gen.2 is an in vitro test for the quantitative determination of cystatin C in human serum and plasma on Roche/Hitachi cobas c systems. Cystatin C measurements are used as an aid in the diagnosis and treatment of renal diseases.

Calibrator:
The C.f.a.s. (Calibrator for automated systems) Cystain C is for use in the calibration of quantitative Roche methods on Roche clinical chemistry analyzers as specified in the value sheets.

Control:
The Cystatin C Control Set Gen.2 is for use in quality control by monitoring accuracy and precision for the quantitative methods as specified in the value sheets.

Roche Tina-quant Cystatin C Gen. 2 reagent provides quantitative measurement of the cystatin C that is present in human serum and plasma. Assay: Reagents are packaged in a cassette with two bottles labeled with their instrument positioning, R1 (Reagent 1) and R2 (Reagent 2). R I contains solution of polymers in MOPS-buffered saline; preservative, stabilizers. R2 is latex particles in glycine buffer coated with anti-Cystatin C antibodies (rabbit); preservative, stabilizers.

Calibrator:
C.f.a.s. Cystatin C is a liquid, ready-to-use calibrator based on pooled delipidated human serum enriched with recombinant human Cystatin C produced in E. Coli. Single level calibrators with lot specific values are diluted on board the analyzer to create a 6-point calibration curve.

Control:
Cystatin C Control Set contains 3 controls based on pooled delipidated human serum enriched with human recombinant Cystatin C produced in E. Coli.

The provided text describes the analytical performance of the Tina-quant Cystatin C Gen. 2 test system. Here's a breakdown of the requested information:

1. Table of Acceptance Criteria and Reported Device Performance

• Control 1 (1.00 mg/L): 1.7%
• Control 2 (1.84 mg/L): 0.9%
• Control 3 (4.12 mg/L): 0.7%
• Human Serum 1 (0.560 mg/L): 1.8%
• Human Serum 2 (2.80 mg/L): 0.6%
• Human Serum 3 (6.39 mg/L): 0.6% |
  | Precision (Intermediate Precision) | Not explicitly stated as a single "acceptance criteria" but implied by the provided data. | Total Imprecision (CV%)
• Control 1 (1.00 mg/L): 2.2%
• Control 2 (1.84 mg/L): 1.4%
• Control 3 (4.12 mg/L): 1.4%
• Human Serum 1 (0.560 mg/L): 2.0%
• Human Serum 2 (2.80 mg/L): 1.3%
• Human Serum 3 (6.39 mg/L): 1.1% |
  | Linearity (Serum) | Reported R² value close to 1 for linear regression. | R² = 0.999 (for Y = 1.001x - 0.0057) |
  | Linearity (Plasma) | Reported R² value close to 1 for linear regression. | R² = 0.999 (for Y = 1.000x + 0.0000) |
  | Lower Limit of Blank (LoB) | LoB claim = 0.30 mg/L | 0.30 mg/L (as the claim) |
  | Lower Limit of Detection (LoD) | LoD claim = 0.40 mg/L | 0.40 mg/L (as the claim) |
  | Lower Limit of Quantitation (LoQ) | LoQ claim = 0.40 mg/L at % CV of 13.3 | 0.40 mg/L at % CV of 13.3 (as the claim) |
  | Endogenous Interference (Hemoglobin, Lipemia, Bilirubin, Rheumatoid Factor) | Recovery within ± 0.100 mg/L of initial values for samples ≤ 1.00 mg/L and within ± 10% for samples > 1.00 mg/L. | All data passed the acceptance criteria; specific interferent limits provided (e.g., Lipemia up to 1000 L index, Hemolysis up to 1000 H index, Bilirubin up to 60 I index, Rheumatoid factor 0.1 mg/L, the deviation must be ≤ ± 10%. | All data passed the acceptance criteria; specific P/B equations provided (e.g., Serum vs. Li-heparin: y = 1.010x + 0.020, r = 1.000). |

2. Sample Size Used for the Test Set and Data Provenance

• Precision and Reproducibility:
  • Test Set: Three human serum samples (0.56, 2.80, and 6.39 mg/L) and three control samples. Each sample was tested in two aliquots per run, two runs per day for 21 days.
  • Data Provenance: Not explicitly stated, but clinical studies are generally performed in a controlled laboratory environment. The context implies it's internal study data.
• Linearity/Assay Reportable Range:
  • Test Set: One batch of reagent, samples measured in triplicate. Two separate dilution series: plasma (thirteen levels) and serum (twenty-one levels).
  • Data Provenance: Not explicitly stated, but internal study data.
• Detection Limit (LoB, LoD, LoQ):
  • Test Set:
    • LoB: One blank sample tested n=5 with two analyzers and three reagent batches for six runs per day across three days.
    • LoD: Five low-analyte samples measured in singlicate on two analyzers with three reagent batches for six runs per day across three days.
    • LoQ: A low-level sample set (prepared by diluting 5 human serum samples) tested in 2 replicates per sample on 5 days, one run per day on one cobas c 501 analyzer.
  • Data Provenance: Not explicitly stated, but internal study data.
• Analytical Specificity (Endogenous Interference):
  • Test Set: One pool of human serum spiked with interferent vs. a second pool without, mixed in different ratios to create a dilution series. Tested at two levels of Cystatin C.
  • Data Provenance: Not explicitly stated, but internal study data.
• Analytical Specificity (Common Drug Interference):
  • Test Set: Two sample pools (low and high Cystatin C) divided into aliquots. One aliquot served as reference; others spiked with drugs. Samples determined in triplicate.
  • Data Provenance: Not explicitly stated, but internal study data.
• Method Comparison with Predicate Device:
  • Test Set: 103 human serum samples.
  • Data Provenance: Not explicitly stated as retrospective or prospective, but likely prospective for the comparison study. The country of origin is not specified.
• Matrix Comparison:
  • Test Set: 57 tubes collected per anticoagulant (Li-heparin, K2-EDTA, K3-EDTA, Gel Separation Tube).
  • Data Provenance: Internal study data.
• Expected Values/Reference Range:
  • Test Set: n=273 subjects from a US panel of healthy subjects.
  • Data Provenance: Prospective study from the US.

3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications

Not applicable. This device is an in-vitro diagnostic test for quantitative determination of Cystatin C. The performance evaluation relies on laboratory measurements and statistical analysis against established analytical performance metrics, not expert interpretation of images or clinical cases for ground truth.

4. Adjudication Method for the Test Set

Not applicable, as the evaluation is based on quantitative measurements and statistical methods, not human interpretation that would require adjudication.

5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was done

No, an MRMC comparative effectiveness study was not done. The context describes an in-vitro diagnostic device, not an imaging or diagnostic aid that would typically involve human readers.

6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was done

Yes, the studies described are standalone performance evaluations of the Tina-quant Cystatin C Gen. 2 test system. The device itself produces quantitative measurements without human-in-the-loop performance influencing the measurement output. The studies evaluate the analytical performance of the system directly.

7. The Type of Ground Truth Used

The "ground truth" for the performance studies is the reference method or expected/true concentration of Cystatin C.

• For precision, it's the statistical variability around the measured mean.
• For linearity, it's the expected linear relationship between serially diluted samples and their measured concentrations.
• For detection limits, it's the inherent chemical/physical limits of the assay.
• For interference studies, it's the known concentration of the analyte without the interferent, and the known concentration of the interferent itself.
• For method comparison, the predicate device's results serve as a comparative "truth" to establish substantial equivalence.
• For matrix comparison, serum results are compared as a baseline for other plasma types.
• For expected values, the ground truth is the statistically derived reference interval from a healthy population.
• For traceability, the device is standardized against the ERM-DA471/IFCC reference material, which acts as the ultimate "ground truth" for Cystatin C measurement.

8. The Sample Size for the Training Set

This information is not provided in the document. The studies described are performance validation studies, not directly describing a machine learning algorithm's "training set." If the device uses an internal algorithm (not specified if it's a machine learning algorithm), the training set for that algorithm is not detailed.

9. How the Ground Truth for the Training Set was Established

This information is not provided in the document. As mentioned above, the document details analytical performance studies rather than the development of a machine learning model's training which would require ground truth establishment for a training set.

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Diazyme Cystatin C Point-of Care (POC) test reagents are intended for use with the SMART analyzer for the quantitative determination of Cystatin C in venous whole blood by latex enhanced immunoturbidimetric method. The measurement of Cystatin C is used as an aid in the diagnosis and treatment of renal disease. For in vitro Diagnostic Use Only.

The Diazyme Cystatin C POC Test Control Kit is intended for use as quality controls for the Cystatin C POC Test. For in vitro Diagnostic Use Only.

Diazyme Cystatin C POC Test Kit contains reagents intended for use with the SMART analyzer for the quantitative determination of Cystatin C (Cys C) in human venous whole blood samples. Measurement of Cystatin C can assist in the assessment of renal transplantation status, monitoring GFR in nephrotoxic drug therapy, and monitoring GFR in acute and chronic kidney diseases including diabetic nephropathy. Cystatin C POC Test reagents are similar to the predicate Diazyme Cystatin C assay reagents (K093680). The similarities and differences in composition and format are noted in Table 1 below. The Cystatin C POC Test is based on a latex enhanced immunoturbidimetric assay. Cystatin C in the venous whole blood sample binds to the specific anti-Cystatin C antibody, which is coated on latex particles, and causes agglutination. The degree of the turbidity caused by agglutination can be measured optically and is proportional to the amount of Cystatin C in the venous whole blood sample. The Cystatin C concentration is expressed as mg/L Cystatin C by use of a lot specific calibration curve that is stored in an RFID card provided with each SMART test kit.

Diazyme Cystatin C POC Test Control Kit is intended for use as quality controls for the Diazyme Cystatin C POC Test and is packaged separately. The controls are made from human venous whole blood and are in a lyophilized (freeze-dried) state. The quality controls assist laboratory users in verification steps ensuring that the assay reagents are functioning correctly. QC materials are run exactly as samples. Users are instructed to verify the calibration curve with the controls and run controls each time a new lot of reagents are received. If OC materials fall outside laboratory acceptable range, users are instructed to re-test and call manufacturer customer service if problem persists.

SMART Analyzer (K092911) is a compact cuvette based spectrophotometer (10 inches x 5.5 inches x 5.5 inches) machine for point-of-care testing designed to analyze readings from single use reagent cuyette. The instrument only uses the Diazyme Reagent System (DRS) cuvette and caps and performs assay with a preprogrammed Radio Frequency ID (RFID) card. The DRS cuvette is supplied prefilled with Reagent 1 (R1) and the DRS cap is supplied prefilled with Reagent 2 (R2). The DRS cuvette and caps are kept separate until use. Users are instructed (see proposed labeling) to add 20ul of sample to the DRS cuvette prefilled with R1 containing proper amount of detergent for venous whole blood lysis. Users are then instructed to snap in place DRS cap and insert into analyzer. The instrument warms the cuvette to 37°C and after a predefined period adds the reagent R2 found in the DRS cap. The reagents and samples are mixed magnetically and absorbance readings are taken at 700nm. The lot specific RFID card contains reagent addition time, mixing time, reading time and calibration curve.

The Diazyme Cystatin C POC Test is a device intended for the quantitative determination of Cystatin C in venous whole blood using a latex-enhanced immunoturbidimetric method with the SMART analyzer. The measurement of Cystatin C aids in the diagnosis and treatment of renal disease.

1. Table of Acceptance Criteria and Reported Device Performance

The provided document does not explicitly state "acceptance criteria" but presents performance characteristics that were evaluated for substantial equivalence to a predicate device. The performance of the Diazyme Cystatin C POC Test is compared against a predicate device (Diazyme Cystatin C Assay, K093680). The table below summarizes the reported performance for the candidate device, which implicitly serves as the performance values that met the substantial equivalence requirements.

• Samples 0.70 mg/L & 0.99 mg/L: 5.6% to 6.9% | The reported CVs for the candidate device are generally within or close to the 1.0 mg/L: 2.2% to 4.9%
• Samples 0.70 mg/L & 0.99 mg/L: 5.6% to 6.9%
  3 POL Sites:
• Samples > 1.0 mg/L: 2.6% to 8.0%
• Samples 0.55 mg/L & 0.93 mg/L: 5.3% to 9.1% |
  | Accuracy (Correlation Coefficient R²) | 0.99 | Diazyme Lab: R² = 0.9867
  3 POL Sites: R² = 0.9872 | Similar |
  | Accuracy (Slope) | 0.99 | Diazyme Lab: 0.9535
  3 POL Sites: 0.955 | Similar |
  | Accuracy (Intercept) | 0.0877 | Diazyme Lab: 0.0985
  3 POL Sites: 0.0732 | Similar |
  | Linearity/Reportable Range (R²) | Not specified | R² = 0.9977 (up to 7.65 mg/L) | Demonstrated strong linearity. |
  | LoB | Not specified | 0.045 mg/L | Established. |
  | LoD | Not specified | 0.11 mg/L | Established. |
  | LoQ | Not specified | 0.30 mg/L | Established, defining the lower end of the AMR. |
  | Interference | Not specified | No significant interference from common substances up to specified concentrations. | Demonstrated analytical specificity. |
  | Expected/Reference Range | Not specified | 0.46 to 1.06 mg/L (in 95% of healthy adults) | Confirmed transferability of reference interval. |

2. Sample 사이즈 used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

• Precision Study:
  • Sample Size: 6 whole blood specimens were tested. Each specimen was run in duplicates, twice a day, over 10 working days on three different SMART Analyzers. This totals (2 runs/day * 2 duplicates/run * 10 days * 3 analyzers) = 120 data points per specimen, but the table reports "Total data points: 40" per specimen for within-run and total precision, implying 40 measurements per specimen over the study period (perhaps per analyzer or across all analyzers).
  • Data Provenance: The study was conducted internally at Diazyme Laboratories, implying internal prospective testing of samples. No specific country of origin is mentioned beyond Diazyme's location in Poway, CA, USA.
• Linearity Study:
  • Sample Size: Eleven levels of Cystatin C concentrations were prepared from a whole blood sample and run in triplicates.
  • Data Provenance: Internal to Diazyme Laboratories.
• LoB, LoD, LoQ:
  • Sample Size: Not explicitly stated but usually involves multiple replicates of blank and low-concentration samples.
  • Data Provenance: Internal to Diazyme Laboratories.
• Interference Study:
  • Sample Size: Two whole blood samples ("low" and "high" Cystatin C) spiked with various concentrations of interfering substances.
  • Data Provenance: Internal to Diazyme Laboratories.
• Method Comparison with Predicate Device (Accuracy Study):
  • Internal Method Comparison:
    • Sample Size: Fifty-five (55) paired human whole blood-serum samples (venous whole blood and plasma from the same individual).
    • Data Provenance: Conducted internally at Diazyme Laboratories, likely prospective.
  • External Method Comparison:
    • Sample Size: One hundred and twenty (120) whole blood samples (40 samples per site) tested at three Point-of-Care (POL) sites. Corresponding plasma specimens (120) were tested with the predicate device.
    • Data Provenance: Conducted externally at three POL sites by intended users, implying prospective testing in real-world settings.
• Expected Values/Reference Range Study:
  • Sample Size: 126 apparently healthy adults.
  • Data Provenance: Whole blood samples were tested using the Diazyme Cystatin C SMART assay, likely collected prospectively for this study, though the specific origin is not stated beyond Diazyme. Age range of participants was 19-63.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

This device is an in vitro diagnostic (IVD) test for quantitative determination of a biomarker (Cystatin C). The "ground truth" for such devices is typically established through reference methods or established assays, rather than expert consensus on interpretive tasks like in imaging.

• For the accuracy/method comparison studies (test set): The predicate device, Diazyme Cystatin C Assay (K093680), run on a Hitachi 917 analyzer, served as the reference method or "ground truth" comparator for the comparison studies. The performance of the predicate device itself would have been established against a recognized gold standard during its own clearance process.
• Number/Qualifications of Experts: The document does not specify experts establishing ground truth in the traditional sense of clinical interpretation. The "experts" involved would be the clinical laboratory professionals operating the predicate device and the new device. Their qualifications are not detailed but are assumed to be standard for clinical laboratory practice.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Not applicable. For quantitative diagnostic tests measuring a biomarker, adjudication methods typically used for qualitative or interpretive tasks (like imaging analysis) are not relevant. The "ground truth" is determined by the result of the reference method (predicate device) and direct comparison of quantitative values. Statistical methods (e.g., regression analysis) are used to assess agreement.

5. 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

Not applicable. This is an in vitro diagnostic device, not an AI-assisted diagnostic imaging or interpretive aid. It directly measures a biomarker. The studies involved comparing the performance of the new device to a predicate device, not the improvement of human reader performance with or without AI.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Yes, the studies present the standalone performance of the Diazyme Cystatin C POC Test System. The device provides a quantitative result for Cystatin C. The performance metrics reported (precision, linearity, accuracy, LoB, LoD, LoQ, interference) reflect the performance of the device system (reagents + SMART analyzer) itself, without direct human cognitive interpretation of the final result for diagnostic purposes. Humans operate the device and interpret the numerical output in the context of clinical guidelines, but the "performance" described is that of the automated measurement system.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

• Method Comparison Studies: The "ground truth" was established by comparison to a legally marketed predicate device (Diazyme Cystatin C Assay, K093680) run on a Hitachi 917 analyzer. This is a common approach for demonstrating substantial equivalence for new IVD devices.
• Other Performance Studies (Precision, Linearity, LoB/LoD/LoQ, Interference): These studies assess the intrinsic analytical performance of the device against predefined analytical standards (e.g., CLSI guidelines), often using prepared control materials or spiked samples where the "true" concentration is known or assumed from the preparation.

8. The sample size for the training set

This document describes a pre-market notification (510(k)) for a traditional IVD device, not a machine learning or AI-driven algorithm. Therefore, the concept of a "training set" in the context of AI model development is not directly applicable here.

The device's calibration curve is established using a lot-specific RFID card provided with each kit. This implies a calibration process performed by the manufacturer, which might involve a set of calibrators, but it's not a "training set" for an AI algorithm.

9. How the ground truth for the training set was established

Not applicable, as no AI/machine learning training set is described for this conventional IVD device. The calibration for the device is performed using a lot-specific calibration curve stored on an RFID card. The accuracy of this calibration would be verified during manufacturing and quality control processes.

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The K-ASSAY® Cystatin C Assay is for the quantitative determination of human cystatin C in serum, EDTA plasma, or lithium heparin plasma by immunoturbidimetric assay. Cystatin C measurements are used as an aid in the diagnosis and treatment of renal diseases. FOR IN VITRO DIAGNOSTIC USE.

The K-ASSAY® Cystatin C Calibrator is intended to be used for the calibration of the K-ASSAY® Cystatin C Assay. FOR IN VITRO DIAGNOSTIC USE.

The K-ASSAY ® Cystatin C Control is intended for use as an assayed quality control material for monitoring the performance of cystatin C assays.

Not Found

The provided text is a 510(k) premarket notification letter from the FDA to Kamiya Biomedical Company regarding their K-ASSAY Cystatin C Assay. It mostly discusses the regulatory approval process and includes a brief "Indications for Use Statement". It does not contain the detailed acceptance criteria and study information typically found in a clinical study report or a detailed 510(k) summary.

Therefore, I cannot extract the specific information you requested. The document does not provide:

• A table of acceptance criteria and reported device performance.
• Sample sizes, data provenance, number/qualifications of experts, or adjudication methods for test sets.
• Information about MRMC comparative effectiveness studies, effect sizes, or standalone algorithm performance.
• Details on the type of ground truth used or how it was established.
• Sample size or ground truth establishment for a training set.

This document is a regulatory approval letter, not a scientific study report. To get the requested information, you would typically need to refer to the full 510(k) submission, specifically the sections detailing analytical and clinical performance studies, which are not included in this letter.

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The Diazyme Cystatin C Assay is an in-vitro diagnostic test for the quantitative determination of Cystatin C in serum or plasma by latex enhanced immunoturbidimetric method. The measurement of Cystatin C is used as an aid in the diagnosis and treatment of renal disease.

Not Found

The provided document is a 510(k) clearance letter for the Diazyme Cystatin C Assay. It states that the device is substantially equivalent to legally marketed predicate devices. However, this document does not contain the detailed study information, acceptance criteria, or performance data typically found in a 510(k) summary or the full submission.

Therefore, I cannot provide a complete answer to your request based solely on the provided text. The document confirms the device's purpose as an in-vitro diagnostic test for Cystatin C to aid in the diagnosis and treatment of renal disease, but it lacks the specific performance data you are asking for.

To answer your questions, I would need access to the 510(k) summary (which usually includes performance data) or the full 510(k) submission for K093680.

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Reagent: For in vitro diagnostic use in the quantitative determination of Cystatin-C (CYSC) in human serum or plasma (lithium heparin, potassium EDTA) on the ADVIA Chemistry systems. Measurement of Cystatin C aids in the diagnosis and treatment of renal disease.

Calibrator: For in vitro diagnostic use in the calibration of Cystatin C method on ADVIA Chemistry systems.

The CYSC latex reagent is a suspension of uniform latex particles coated with anticystatin-C antibody. When serum or plasma containing cystatin C is mixed with the latex reagent, agglutination takes place resulting in an increase in turbidity. This turbidity is measured at 571 and 805 nm. The cystatin C concentration in serum or plasma is determined from a calibration curve that is generated with the calibrators.

Here's an analysis of the provided text regarding the acceptance criteria and supporting study for the ADVIA® Chemistry Cystatin C Method:

1. Table of Acceptance Criteria and Reported Device Performance

The provided text does not contain explicit, quantitative acceptance criteria for device performance. Instead, it relies on demonstrating substantial equivalence to an existing predicate device (Dade Behring N Latex Cystatin C and Dade Behring N Protein Standard UY). The "performance" is implicitly deemed acceptable if it closely matches or is considered equivalent to the predicate device in various aspects.

Therefore, the table below reflects the comparative information provided rather than explicit acceptance criteria.

2. Sample Size Used for the Test Set and Data Provenance

The document states: "Comparative testing described in the protocol included in this submission demonstrates substantial equivalent performance."

• Sample Size for Test Set: The specific sample size for the comparative testing (test set) is not explicitly mentioned in the provided text.
• Data Provenance: The country of origin and whether the data was retrospective or prospective is not explicitly mentioned. Given it's a submission to the FDA in the US, it's highly probable that some or all of the data generation occurred in the US or under US regulatory guidelines.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

This type of information (experts, qualifications) is typically related to diagnostic imaging or clinical interpretation where human judgment is a critical component of ground truth. For an in vitro diagnostic (IVD) like a Cystatin C blood test, the "ground truth" for the test set would be established by reference methods or validated laboratory results, not by human experts interpreting clinical data in the same way a radiologist would interpret an image.

Therefore, this information is not applicable in the context of this device and is not mentioned in the document.

4. Adjudication Method for the Test Set

Similar to point 3, adjudication methods (like 2+1, 3+1) are for resolving discrepancies in human expert interpretations. For an IVD, the "adjudication" would involve technical verification of reference methods and statistical comparison of analytical results.

Therefore, an adjudication method in this sense is not applicable and is not mentioned.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

An MRMC study is relevant for devices where multiple human readers interpret results, and the device's main benefit is to improve human reader performance (e.g., CAD for radiology). For an in vitro diagnostic like a Cystatin C assay, the device directly measures a biomarker; there is no "human reader" in the sense of interpreting complex diagnostic images or clinical scenarios.

Therefore, an MRMC study was not performed and is not applicable to this device type.

6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study

Yes, a standalone performance assessment was effectively done. The entire premise of this 510(k) submission is to demonstrate the analytical performance of the ADVIA Chemistry Cystatin C Method as a standalone assay, comparing its analytical characteristics (e.g., intended use, antibody, format, traceability, reference range, reportable range) directly against the predicate device. The performance data would primarily be objective analytical measurements from the device itself.

7. Type of Ground Truth Used

For this in vitro diagnostic device, the "ground truth" would be established by:

• Reference methods: Highly accurate and precise laboratory methods for measuring Cystatin C.
• Established analytical performance characteristics: The predicate device itself serves as a benchmark for "ground truth" in terms of expected analytical performance and clinical utility. The new device demonstrates substantial equivalence to these established characteristics.
• Internal standards of highly purified human cystatin C: Used for traceability and calibration, indicating a defined chemical standard as part of establishing the truth for concentration measurements.

8. Sample Size for the Training Set

• The document does not specify the sample size used for the training set. For an IVD, "training" typically refers to the development of calibration curves and optimization of the assay parameters rather than a classical machine learning training set with labeled data in the same way an AI model is trained.

9. How the Ground Truth for the Training Set Was Established

For an IVD like this, the "ground truth" for developing or "training" the assay (e.g., establishing calibration curves, optimizing reagents) would likely be established through:

• Known concentrations of purified Cystatin C: Used to create calibration standards (as hinted by "internal standard of highly purified human cystatin C").
• Standard laboratory methods: Validated methods to assign target values to control materials and calibrators.
• Clinical panels: Samples from individuals with known physiological states (e.g., healthy controls, patients with renal disease at various stages) might be used during development to assess clinical correlation, though the analytical ground truth comes from quantitative measures.

The document directly mentions the use of "internal standard of highly purified human cystatin C" for traceability of calibrators, which is a key aspect of establishing ground truth for the quantitative measurement.

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