(61 days)
The Rheumatoid Factor assay is used for the quantitation of rheumatoid factor (antibodies to immunoglobulins) in human serum or plasma. Measurement of rheumatoid factor may aid in the diagnosis of rheumatoid arthritis.
Rheumatoid Factor is an in vitro diagnostic assay for the quantitative determination of rheumatoid factor in human serum or plasma. The rheumatoid factor, an autoimmune antibody, in the sample interacts with the aggregated (denatured) human gamma globulin in the reagent forming immune complexes. The immune complexes cause an increase in light scattering, measured at 340 and 700 nm, which correlates with the concentration of rheumatoid factor in the sample.
Here's an analysis of the provided text regarding the Abbott Laboratories Rheumatoid Factor assay, focusing on acceptance criteria and the study proving its performance:
1. Table of Acceptance Criteria and Reported Device Performance
The submission doesn't explicitly state "acceptance criteria" in a clear, quantitative, pre-defined manner. Instead, it demonstrates performance through comparative studies, implying that similar performance to the predicate device is the acceptance criterion for substantial equivalence.
| Performance Metric | Acceptance Criteria (Implied by Predicate) | Reported Device Performance (Abbott RF Assay) |
|---|---|---|
| Correlation with Predicate Device | Acceptable correlation with K-ASSAY® Rheumatoid Factor assay on Hitachi® 717 Analyzer | Correlation coefficient = 0.9883, slope = 1.082, Y-intercept = -3.168 U/mL |
| Precision (Total %CV) | Similar precision to K-ASSAY® Rheumatoid Factor assay (not explicitly stated, but implied as "acceptable") | Level 1/Panel 502: 5.2% Total %CV |
| Level 2/Panel 503: 2.2% Total %CV | ||
| Assay Range | A specific range of quantitation | 0.76 to 413.08 U/mL |
| Limit of Quantitation (Sensitivity) | A specific lower limit of quantitation | 2.97 U/mL |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the sample size used for the comparative performance studies.
- Sample Size (Test Set): Not specified.
- Data Provenance: Not specified (e.g., country of origin, retrospective or prospective).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
This information is not applicable and not mentioned. The "ground truth" in this context is the quantitative result from the predicate device (K-ASSAY® Rheumatoid Factor assay on the Hitachi® 717 Analyzer), not expert clinical adjudication.
4. Adjudication Method for the Test Set
This is not applicable as the "test set" involves comparing quantitative assay results to a predicate device, not subjective interpretation requiring adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
No, an MRMC comparative effectiveness study was not done. This device is an in vitro diagnostic assay, not an imaging or diagnostic AI tool that would typically involve human readers interpreting cases.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
Yes, the performance characteristics described (correlation, precision, assay range, limit of quantitation) are standalone algorithm-only performance metrics for the Rheumatoid Factor assay. There is no human-in-the-loop component mentioned for the diagnostic process itself.
7. The Type of Ground Truth Used
The "ground truth" used for comparison was the results obtained from the legally marketed predicate device, the K-ASSAY® Rheumatoid Factor assay on the Hitachi® 717 Analyzer. This represents a "device-to-device" comparison for establishing substantial equivalence.
8. The Sample Size for the Training Set
This information is not applicable and not mentioned. This is not a machine learning or AI-based device that undergoes a "training phase" in the conventional sense. It's a chemical immunoassay; its "training" or development would involve formulation and optimization rather than data-driven model training.
9. How the Ground Truth for the Training Set was Established
As explained above, this concept of a "training set" and "ground truth for training" is not relevant to this type of immunoassay device. The assay development would rely on established biochemical principles and analytical validation rather than a data training process.
§ 866.5775 Rheumatoid factor immunological test system.
(a)
Identification. A rheumatoid factor immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the rheumatoid factor (antibodies to immunoglobulins) in serum, other body fluids, and tissues. Measurement of rheumatoid factor may aid in the diagnosis of rheumatoid arthritis.(b)
Classification. Class II (performance standards).