(57 days)
The ACCESS® Total βhCG assay is a paramagnetic-particle, chemiluminescent immunoassay for the quantitative determination of total βhCG in human serum, using the the ACCESS® Immunoassay System.
The Access® Total BhCG reagents and the Access® Immunoassay Analyzer comprise the Access® Immunoassay System for the quantitative determination of total βhCG levels in human serum.
The document describes the acceptance criteria and supporting studies for the Access® Total βhCG assay.
Here's a breakdown of the requested information:
1. Table of acceptance criteria and the reported device performance:
| Acceptance Criteria Category | Specific Metric (Criteria) | Reported Device Performance |
|---|---|---|
| Precision | Within-run precision: Not explicitly stated as a criterion, but demonstrated. | Ranges from 1.34% CV |
| Total imprecision: Not explicitly stated as a criterion, but demonstrated. | Ranges from 2.41% CV to 3.38% CV | |
| Accuracy | Dilution recovery: Mean recoveries for two human serum samples. | 97% and 98% (for dilutions from 1:1.2 to 1:32) |
| Correlation | Comparison with predicate device (ACS:180 Total hCG +B assay): Slope and correlation coefficient (r) for 119 human serum samples. | Slope = 0.914, r = 0.98 |
| Analytical Sensitivity | Lowest detectable level of βhCG distinguishable from zero. | 0.5 mIU/ml |
| Analytical Specificity | Cross-reactivity with hLH, hFSH, or hTSH. | No significant cross-reactivity observed. |
| Molar percent specificity of free βhCG subunit (WHO 75/551). | Approximately 200% | |
| Hook Effect | Absence of hook effect at high concentrations. | No discernible hook effect at 1,000,000 mlU/ml. (Predicate assay: patient samples as high as 400,000 mlU/ml will assay > 1000 mlU/ml). |
| Assay Range | Measurement range. | 0.5 mIU/ml - 1000 mIU/ml |
2. Sample size used for the test set and the data provenance:
- Correlation Study (comparison with predicate): 119 human serum samples.
- Accuracy (Dilution Recovery): 2 human serum samples were diluted.
- Precision: Not explicitly stated how many samples were used, but multiple runs/measurements would be implied by CV calculation.
- Analytical Sensitivity: Data supports the lowest detectable level using Access® Total βhCG Calibrator S0.
- Analytical Specificity: Not specified.
- Data Provenance: The data used for these studies are described as "human serum samples." The document does not specify the country of origin of the data, nor does it explicitly state whether the study was retrospective or prospective. Given the nature of these types of lab validation studies, they are typically prospective evaluations of samples.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
This device is an in-vitro diagnostic (IVD) assay used for the quantitative determination of βhCG. The "ground truth" for this type of device is established by the known concentration of βhCG in control materials or by comparison with a well-established and standardized reference method. The document does not mention human expert adjudication for establishing ground truth in the context of image interpretation or subjective assessments. Instead, it refers to:
- Standardization: "Both assays are standardized to the WHO 3rd IS 75/537 standard." This international standard serves as the "ground truth" for hCG concentration.
- Predicate Device Comparison: The ACS:180 Total hCG +B assay acts as a comparative reference, implying its results are considered a form of "ground truth" for comparison purposes.
Therefore, no human experts (e.g., radiologists) were used in the way one might for diagnostic imaging studies, as the ground truth is based on biochemical standards and established comparative assays.
4. Adjudication method for the test set:
Not applicable in the context of this IVD device. "Adjudication" usually refers to resolving discrepancies between multiple human readers or a human reader and an AI. For this quantitative immunoassay, the "ground truth" is determined by reference standards and established analytical methods, not human opinion or consensus.
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 assay, not an AI-assisted diagnostic imaging or human-in-the-loop system. Therefore, MRMC studies and "improvement with AI vs without AI assistance" are not relevant to this device.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
Yes, the studies describe the performance of the Access® Total βhCG assay as a standalone system (algorithm/reagent-only) when run on the Access® Immunoassay Analyzer. The results reported for precision, accuracy, analytical sensitivity, and specificity represent the performance of the device without human interpretation or intervention beyond the standard operation of the instrument.
7. The type of ground truth used:
The ground truth for this device's performance studies relies on:
- Reference Standards: The WHO 3rd IS 75/537 standard for hCG concentration.
- Known Concentrations: In spiked samples or controls for dilution recovery.
- Comparative Reference Method: The ACS:180 Total hCG +B assay is used as a comparative "ground truth" for correlation studies.
- Analytical Definitions: For sensitivity (lowest detectable level) and specificity (cross-reactivity with other hormones).
8. The sample size for the training set:
The document does not describe a "training set" in the context of machine learning. This is an immunoassay, not a machine learning algorithm that requires a separate training set. The assay's performance characteristics (e.g., calibration curves, sensitivity parameters) are established through a validation process, but this is distinct from training a machine learning model.
9. How the ground truth for the training set was established:
Not applicable, as there is no "training set" in the machine learning sense for this immunoassay. The standardization of the assay's calibration curve and parameters would be established by running known concentrations of calibrators (e.g., Access® Total βhCG Calibrator S0).
§ 862.1155 Human chorionic gonadotropin (HCG) test system.
(a)
Human chorionic gonadotropin (HCG) test system intended for the early detection of pregnancy —(1)Identification. A human chorionic gonadotropin (HCG) test system is a device intended for the early detection of pregnancy is intended to measure HCG, a placental hormone, in plasma or urine.(2)
Classification. Class II.(b)
Human chorionic gonadotropin (HCG) test system intended for any uses other than early detection of pregnancy —(1)Identification. A human chorionic goadotropin (HCG) test system is a device intended for any uses other than early detection of pregnancy (such as an aid in the diagnosis, prognosis, and management of treatment of persons with certain tumors or carcinomas) is intended to measure HCG, a placental hormone, in plasma or urine.(2)
Classification. Class III.(3)
Date PMA or notice of completion of a PDP is required. As of the enactment date of the amendments, May 28, 1976, an approval under section 515 of the act is required before the device described in paragraph (b)(1) may be commercially distributed. See § 862.3.