(45 days)
The Calcium assay is used for the quantitation of calcium in human serum, plasma, or urine. Calcium measurements are used in the diagnosis and treatment of parathyroid disease, a variety of bone diseases, chronic renal disease, and tetany (intermittent muscular contractions or spasms).
Calcium is an in vitro diagnostic assay for the quantitative determination of calcium in serum, plasma, or urine. The Calcium assay is a clinical chemistry assay in which arsenazo-III dye reacts with calcium in an acid solution to form a blue-purple complex. The color developed is measured at 600 nm and is proportional to the calcium concentration in the sample.
Here's an analysis of the provided information regarding the Calcium assay, focusing on acceptance criteria and the study conducted:
1. Table of Acceptance Criteria and Reported Device Performance
The submission doesn't explicitly state "acceptance criteria" in a quantified manner beyond "acceptable correlation." Instead, it uses the performance of a predicate device as the benchmark for substantial equivalence.
| Performance Metric | Acceptance Criteria (Implied by Predicate) | Reported Device Performance (Calcium assay vs. Boehringer Mannheim Calcium on Hitachi 717) |
|---|---|---|
| Serum Application | ||
| Correlation Coefficient | Strong correlation (similar to predicate) | 0.9624 |
| Slope | Close to 1.0 (similar to predicate) | 0.979 |
| Y-intercept | Close to 0 (similar to predicate) | 0.492 mg/dL |
| Within-run %CV (Level 1) | Low variability (similar to predicate) | 1.7% |
| Within-run %CV (Level 2) | Low variability (similar to predicate) | 2.9% |
| Overall Total %CV | Low variability (similar to predicate) | 1.7% (Level 1) / 2.9% (Level 2) |
| Urine Application | ||
| Correlation Coefficient | Strong correlation (similar to predicate) | 0.9981 |
| Slope | Close to 1.0 (similar to predicate) | 0.989 |
| Y-intercept | Close to 0 (similar to predicate) | -0.094 mg/dL |
| Within-run %CV (Level 1) | Low variability (similar to predicate) | 6.8% |
| Within-run %CV (Level 2) | Low variability (similar to predicate) | 3.1% |
| Overall Total %CV | Low variability (similar to predicate) | 6.8% (Level 1) / 3.1% (Level 2) |
| General | ||
| Linearity | Range similar to predicate | Up to 18 mg/dL |
| Limit of Quantitation (Sensitivity) | Similar to predicate | 0.865 mg/dL |
| Clinical Results | Yield similar clinical results (Qualitative) | "Both assays yield similar clinical results." |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: The document does not explicitly state the number of individual patient samples (test set) used for the comparative performance studies. It mentions "two levels of control material" for precision studies. For the method comparison, it implies a patient sample set was used to generate correlation, slope, and intercept, but the size is not quantified.
- Data Provenance: Not specified. It's an in vitro diagnostic assay, so it's likely laboratory-based data. The country of origin and whether it's retrospective or prospective data are not mentioned.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This type of information is generally not applicable to a clinical chemistry assay like a calcium assay. The "ground truth" for a quantitative analyte is typically established by the reference method (in this case, the Boehringer Mannheim Calcium assay on the Hitachi 717 Analyzer) or by a highly accurate laboratory method. There are no human experts involved in visually interpreting or diagnosing based on the raw calcium measurement for ground truth establishment in this context.
4. Adjudication Method for the Test Set
Not applicable. This is a quantitative assay comparison against a predicate device, not a diagnostic interpretation that requires expert adjudication.
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 not an AI-assisted diagnostic device, nor does it involve human readers interpreting images or data. It's a quantitative in vitro diagnostic assay.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, this study is inherently "standalone" in the sense that it evaluates the performance of the Calcium assay itself (the "algorithm" being the chemical reaction and measurement process) against a reference standard. There is no human interpretation or intervention in the measurement process itself that alters the output of the device.
7. The Type of Ground Truth Used
The ground truth or reference standard used for comparison is the Boehringer Mannheim® Calcium assay on the Hitachi® 717 Analyzer. This is a well-established, legally marketed predicate device, serving as the benchmark for acceptable performance. The study aims to demonstrate that the new Calcium assay yields "similar clinical results" and highly correlated quantitative measurements to this predicate.
8. The Sample Size for the Training Set
Not applicable in the context of this device. This is a traditional chemical assay, not a machine learning or AI-driven device that requires a "training set" in the computational sense. The assay's parameters (reagents, reaction conditions, measurement wavelength) are intrinsically defined by its chemical methodology, not by being "trained" on a dataset.
9. How the Ground Truth for the Training Set Was Established
Not applicable (as per point 8).
§ 862.1145 Calcium test system.
(a)
Identification. A calcium test system is a device intended to measure the total calcium level in serum. Calcium measurements are used in the diagnosis and treatment of parathyroid disease, a variety of bone diseases, chronic renal disease and tetany (intermittent muscular contractions or spasms).(b)
Classification. Class II.