(57 days)
The ARCHITECT™ Total T (TT ) assay is a Chemiluminescent Microparticle Immunoassay (CMIA) for the quantitative determination of thyroxine (total T.) in human serum and plasma. The ARCHITECT Total T assay is to be used as an aid in the assessment of thyroid status.
ARCHITECT Total T, is a Chemiluminescent Microparticle Immunoassay (CMIA) for the quantitative determination of total T , in human serum or plasma (lithium heparin, sodium heparin. or potassium EDTA). ARCHITECT Total T, is calibrated with ARCHITECT Total T, Calibrators. ARCHITECT Total T, Controls are assayed for the verification of the accuracy and precision of the Abbott ARCHITECT i System.
Here's an analysis of the provided text regarding the Abbott ARCHITECT™ Total T device, focusing on acceptance criteria and study details:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criterion | Reported Device Performance |
|---|---|
| Correlation Coefficient (Least Squares) | 0.928 |
| Slope (Least Squares) | 1.01 |
| Y-axis Intercept (Least Squares) | -0.11 ug/dL |
| Correlation Coefficient (Passing-Bablok) | 0.928 |
| Slope (Passing-Bablok) | 0.99 |
| Y-axis Intercept (Passing-Bablok) | -0.13 ug/dL |
Note: The document only states the reported performance metrics. It does not explicitly define pre-specified acceptance criteria (e.g., "correlation coefficient > 0.95"). However, the statement "In conclusion, these data demonstrate that the ARCHITECT Total T2 assay is as safe and effective as, and is substantially equivalent to, the AxSYM Total Ta assay" implies that these performance metrics met the internal or regulatory standards for demonstrating substantial equivalence.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 1155 specimens
- Data Provenance: The document does not specify the country of origin of the data. It also does not explicitly state whether the study was retrospective or prospective. Given the nature of a comparison study using existing specimens or collected for this purpose, it could be either, but retrospective analysis of banked samples is common for method comparisons.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This information is not provided in the document. The study is a method comparison between two assays, not a diagnostic accuracy study against a clinical ground truth established by experts. The "ground truth" in this context is the result from the predicate device (AxSYM® Total T. assay).
4. Adjudication Method for the Test Set
This information is not applicable/not provided. Adjudication typically applies to studies where multiple experts independently review data and their interpretations are then reconciled. This study is an analytical comparison of an investigational device against a predicate device.
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
This information is not applicable. This is an analytical device comparison study, not an AI-assisted diagnostic study involving human readers.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This study is a standalone performance assessment of the ARCHITECT™ Total T device against a predicate device. There is no human-in-the-loop component mentioned; it is a direct comparison of the quantitative results from the two assays.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
The "ground truth" for this study was the results obtained from the legally marketed predicate device, the AxSYM® Total T. assay. The new device's performance was compared directly to the predicate device's output on the same specimens.
8. The Sample Size for the Training Set
This information is not provided and is likely not relevant as this is an immunoassay device, not a machine learning or AI algorithm that typically requires a distinct training set. The device is "calibrated with ARCHITECT Total T, Calibrators," which serve a similar function in establishing the measurement curve, but this isn't typically referred to as a "training set" in the context of AI/ML.
9. How the Ground Truth for the Training Set Was Established
This information is not provided and is not applicable in the same way it would be for an AI/ML device. The "ground truth" for calibration in an immunoassay refers to the assigned values of the calibrator materials, which are typically established through a rigorous process of reference methods and standardization.
§ 862.1700 Total thyroxine test system.
(a)
Identification. A total thyroxine test system is a device intended to measure total (free and protein bound) thyroxine (thyroid hormone) in serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of thyroid diseases.(b)
Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.