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The GSP Neonatal 17α-OH-progesterone kit is intended for the quantitative determination of human 17α-OH-progesterone in blood specimens dried on filter paper as an aid in screening newborns for congenital adrenal hyperplasia (CAH) using the GSP™ instrument.

The GSP Neonatal 17x-OH-progesterone (17-OHP) assay is a solid phase, time-resolved fluoroimmunoassay based on the competitive reaction between europium-labeled 17-OHP and sample 17-OHP for a limited amount of binding sites on 17-OHP specific polyclonal antibodies (derived from rabbit). Danazol facilitates the release of 17-OHP from the binding proteins. A second antibody, directed against rabbit IgG, is coated to the solid phase, giving convenient separation of the antibody-bound and free antigen. DELFIA Inducer dissociates europium ions from the labeled antigen into solution where they form highly fluorescent chelates with components of DELFIA Inducer. The fluorescence in each well is then measured. The fluorescence of each sample is inversely proportional to the concentration of 17-OHP in the sample.

The provided text describes the GSP Neonatal 17α-OH-progesterone kit and its comparison to a predicate device, the AutoDELFIA Neonatal 17α-OH-progesterone kit. The primary study presented focuses on the "Screening Efficacy" of the new GSP kit by comparing its results to those of the predicate device using various percentile cut-offs.

Here's an analysis of the acceptance criteria and study information:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state formal "acceptance criteria" in a quantitative manner (e.g., "The device must achieve X% accuracy"). Instead, it demonstrates performance by comparing the new device (GSP kit) to the legally marketed predicate device (AutoDELFIA kit) and showing high agreement.

The screening efficacy tables (Tables 1-9) implicitly demonstrate the device's acceptable performance based on its agreement with the predicate device. For the purpose of this analysis, we will consider the "Overall percent agreement" with the predicate device as the key performance metric presented.

2. Sample size used for the test set and the data provenance

• Test Set Sample Size: A total of 2589 specimens were evaluated across all weight categories and cut-offs.
  • ≥2500g: 1842 specimens (Tables 1, 4, 7)
  • 1250g-2249g: 439 specimens (Tables 2, 5, 8)
  • <1250g: 308 specimens (Tables 3, 6, 9)
  • Additionally, 23 known CAH cases were included within these 2589 samples.
  • For the general method comparison (Y= 0.97x + 0.27; r = 0.96), 2567 samples were compared.
• Data Provenance: The study used retrospective archived specimens and leftover samples from specimens submitted for routine screening. The document does not specify the country of origin of the data, but it states the study was conducted "in one newborn screening laboratory."

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

The document does not mention the use of experts to establish ground truth for this comparison study. Instead, the "ground truth" for the screening efficacy study is implicitly defined by the results of the predicate device (AutoDELFIA Neonatal 17α-OH-progesterone kit). The 23 "known CAH cases" would have had their diagnosis established through other means, likely clinical follow-up and definitive diagnostic tests, which are not detailed in this report.

4. Adjudication method for the test set

There is no mention of an adjudication method in the context of comparing the GSP kit to the AutoDELFIA kit. The comparison directly uses the test results from both devices.

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 is not applicable. The device described is a quantitative in vitro diagnostic (IVD) kit for measuring 17α-OH-progesterone, not an AI-assisted diagnostic tool that involves human readers interpreting images or results. Therefore, no MRMC study or AI assistance effect size is discussed.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Yes, the performance presented for the GSP Neonatal 17α-OH-progesterone kit is a standalone (algorithm only) performance. The kit is designed to quantitatively determine 17α-OH-progesterone levels in blood specimens using the GSP™ instrument; it does not involve human interpretation in the workflow described for the direct comparison.

7. The type of ground truth used

The primary "ground truth" against which the new device's performance is measured is the predicate device's performance (AutoDELFIA Neonatal 17α-OH-progesterone kit). This is a common approach for demonstrating substantial equivalence for new IVD devices.

Additionally, the study included 23 known CAH cases, indicating that these cases had a definitive diagnosis of Congenital Adrenal Hyperplasia, likely established through a combination of clinical outcomes, follow-up testing, and potentially genetic analysis, although the specific details are not provided. These cases served as a validation point within the overall sample set.

8. The sample size for the training set

The document describes a device comparison and does not explicitly reference a "training set" in the context of machine learning or algorithm development. This is an IVD kit, where performance is typically established through analytical and clinical validation studies rather than machine learning training.

9. How the ground truth for the training set was established

As there is no mention of a separate "training set" for an algorithm in this context, information on how its ground truth was established is not provided. The calibrators and controls used for the kit itself would be part of the manufacturing quality control and calibration process, established using gravimetric methods and human blood matrix (as mentioned in Table 1).

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