(13 days)
The Vitalab Uric Acid Reagent Kit is intended for use with the Vitalab Selectra Analyzer as a system for the quantitative determination of uric acid in serum and plasma. Uric acid results may be used for the diagnosis and treatment of numerous renal and metabolic disorders, including renal failure, gout, leukemia, psoriasis, starvation or other wasting conditions, and of patients receiving cytotoxic drugs.
The Vitalab Uric Acid Reagent is a two-part for use with the Vitalab Selectra Analyzer. This reagent determines uric acid through enzymatic oxidation by uricase linked to a Trinder indicator reaction utilizing N-ethyl-N-(bydroxy-3sulfopropyl)-toluidine (TOOS) and 4-aminoantipyrine.
Here's a breakdown of the acceptance criteria and study information for the Vitalab Uric Acid Reagent, based on the provided text:
Acceptance Criteria and Device Performance
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Linear Range | Recovery of linearity standards that span the linear range, showing good correlation. | 0.1 to at least 25 mg/dL. |
| Regression: (Vitalab Recoveries) = 0 mg/dL + 1.027 x (Concentration), r = 0.999, s.y = 0.12 mg/dL, n = 40 | ||
| Detection Limit | Mean + two standard deviations of normal saline measurements should be rounded up to the smallest reportable value. | 0.1 mg/dL (mean + 2SD of normal saline measurements was 0.0 mg/dL, rounded up to the round-off error of the assay). |
| Precision | Replicate assay of commercially available control serum should demonstrate acceptable within-run and total precision (specific thresholds not explicitly stated but implied by acceptable results). | Serum 1 (2.5 mg/dL): Within Run: 1SD = 0.02, %CV = 0.7%; Total: 1SD = 0.04, %CV = 1.6% |
| Serum 2 (6.8 mg/dL): Within Run: 1SD = 0.04, %CV = 0.7%; Total: 1SD = 0.09, %CV = 1.4% | ||
| Serum 3 (11.1 mg/dL): Within Run: 1SD = 0.07, %CV = 0.6%; Total: 1SD = 0.13, %CV = 1.2% | ||
| Correlation | Good agreement with a "another commercially available method" (predicate device). Implied by a strong correlation coefficient and acceptable Deming regression statistics. | Serum: Selecta = 0.05 mg/dL + 0.995 x Competitive Reagent, r = 0.995, s.y = 0.08 mg/dL, n = 120 |
| Plasma: Selecta = 0.05 mg/dL + 0.995 x Competitive Reagent, r = 0.995, s.y = 0.08 mg/dL, n = 120 | ||
| Stability | All statistical estimates of total imprecision to be less than 0.2 mg/dL for claimed periods. | Onboard reagent stability: 14 days; Calibration stability: 7 days. Statistical estimates of total imprecision less than 0.2 mg/dL in all cases. |
2. Sample Size Used for the Test Set and Data Provenance
- Linear Range: n = 40 (number of recovery samples for linearity standards)
- Detection Limit: n = 30 (normal saline assays)
- Precision: n = 60 for each of the 3 serum samples (total 180 individual measurements).
- Correlation: n = 60 serum specimens and n = 60 heparinized plasma specimens (total n = 120 patient specimens).
- Data Provenance: The text states, "Sixty serum specimens ranging from 3.6 to 10.2 mg/dL uric acid and 60 heparinized plasma specimens ranging from 2.1 to 10.6 mg/dL uric acid were collected from adult patients..." This indicates the data is prospective (collected for the study) from adult patients, but the country of origin is not specified.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- This device is a reagent for diagnostic testing, not an imaging or AI system that requires expert interpretation to establish ground truth for performance evaluation.
- The "ground truth" (or reference method) for the correlation study was "another commercially available method" (the predicate device). No human experts were explicitly involved in establishing "ground truth" in the manner of medical imaging interpretation.
4. Adjudication Method for the Test Set
- Not applicable. This is a chemical reagent and an analytical performance study, not an imaging or diagnostics study requiring adjudication of interpretations. The performance is assessed by comparing results to a reference method (the predicate device) or by intrinsic analytical measures (precision, linearity).
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 a study of a chemical reagent, not an AI-based diagnostic tool requiring human-in-the-loop evaluation or MRMC studies.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Not applicable. This is a study of a chemical reagent, not an algorithm. The performance described is the standalone analytical performance of the reagent on the Vitalab Selectra Analyzer.
7. The Type of Ground Truth Used
- Linear Range: The ground truth was based on the known concentrations of "linearity standards."
- Detection Limit: The ground truth was normal saline (assumed to have 0 mg/dL uric acid).
- Precision: The ground truth was the known mean concentration of "commercially available control serum."
- Correlation: The ground truth was established by the results from a "another commercially available method" (the predicate device). This serves as the reference method against which the new device's performance is compared.
8. The Sample Size for the Training Set
- Not applicable. This is a chemical reagent, not a machine learning algorithm that requires a "training set." The performance characteristics are determined through analytical testing.
9. How the Ground Truth for the Training Set Was Established
- Not applicable, as there is no "training set" for a chemical reagent.
§ 862.1775 Uric acid test system.
(a)
Identification. A uric acid test system is a device intended to measure uric acid in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of numerous renal and metabolic disorders, including renal failure, gout, leukemia, psoriasis, starvation or other wasting conditions, and of patients receiving cytotoxic drugs.(b)
Classification. Class I (general controls). The device, when it is solely intended for use as an acid reduction of ferric ion test, a phosphotungstate reduction test, a gasometric uricase test, an ultraviolet uricase test, or an oxygen rate uricase test, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.