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The LIAISON® Testosterone xt is a direct, competitive, chemiluminescence immunoassay (CLIA) intended for the quantitative determination of testosterone in human serum and EDTA plasma on the LIAISON® XL Analyzer. The assay is intended for in vitro diagnostic use.

Measurement of testosterone is used in the diagnosis and treatment of disorders involving the male sex hormones (androgens), including primary and secondary hypogonadism, delayed or precocious puberty, impotence in males and, in females hirsutism (excessive hair) and virilization (masculinization) due to tumors, polycystic ovaries, and adrenogenital syndromes.

The test has to be performed on the LIAISON® XL Analyzer.

The LIAISON® Testosterone xt assay's method for quantitative determination of testosterone is a direct, competitive, chemiluminescence immunoassay (CLIA). Specific antibody to testosterone is bound to magnetic particles (solid phase) and testosterone is linked to an isoluminol derivative. During the incubation, testosterone is dissociated from its binding protein and competes with labeled testosterone for binding sites on the antibody. After the incubation, the unbound material is removed with a wash cycle. Subsequently, the starter reagents are added and a flash chemiluminescent reaction is initiated. The light signal is measured by a photomultiplier as relative light units (RLU) and is inversely proportional to the concentration of testosterone present in calibrators, controls, or samples.

The LIAISON® Testosterone xt is an in vitro diagnostic device consisting of reagents provided in individual compartments within a plastic container called the Reagent Integral. The components provided in the unitized Reagent Integral include: PMP (paramagnetic particles), conjugate and assay buffer. All reagents in the integral are supplied ready to use. The assay configuration for the LIAISON® Testosterone xt allows for the performance of 100 tests.

The two-point calibrators are provided in the same kit box, but separate from the Reagent Integral. The two-point calibrators are supplied ready to use.

The LIAISON® Testosterone xt assay is performed on the LIAISON® XL Analyzer (Model 10050; originally FDA cleared under K103529), a fully automated system with continuous loading combining the chemiluminescence technology with magnetic microparticles as the solid phase.

Here's a breakdown of the acceptance criteria and study information for the LIAISON® Testosterone xt device, extracted from the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

2. Sample Size for the Test Set and Data Provenance

The provided document does not explicitly state the sample sizes used for each specific test (e.g., method comparison, precision, linearity, recovery). It only summarizes the results in "Table 6-2: Comparison to Predicate Device" and refers to "verification and validation activities" without detailing the exact number of samples for each.

The data provenance is not specified in terms of country of origin. The studies appear to be retrospective analyses of device performance characteristics, as they involve testing the LIAISON® Testosterone xt against existing methods or conditions to demonstrate equivalence and improved performance over the predicate device.

3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications

This information is not explicitly provided in the document. For the "Method Comparison," it refers to "commercially available immunoassay" and "CDC HoSt Testosterone RMP ID-LC-MS/MS values." The latter, CDC HoSt Testosterone RMP ID-LC-MS/MS, likely represents a highly accurate and standardized reference method, which serves as a widely accepted ground truth in laboratory medicine, rather than relying on individual expert consensus for each measurement. No human experts are mentioned for ground truth establishment.

4. Adjudication Method for the Test Set

No explicit adjudication method is mentioned. The studies focus on direct quantitative analytical performance comparisons rather than subjective human interpretation.

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 LIAISON® Testosterone xt is an in vitro diagnostic device, specifically a chemiluminescence immunoassay (CLIA), for the quantitative determination of testosterone. It is an automated laboratory test, not an AI-assisted diagnostic imaging or interpretation tool that involves human readers. Therefore, an MRMC comparative effectiveness study involving human readers and AI is not relevant to this device.

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

Yes, this is effectively a standalone device performance study. The LIAISON® Testosterone xt is an automated system where the measurement of testosterone is performed by the analyzer (LIAISON® XL Analyzer) without human intervention in the analytical process itself. The performance metrics (LoB, LoD, LoQ, precision, linearity, recovery) are all measures of the algorithm's and instrument's direct analytical capability.

7. The Type of Ground Truth Used

The ground truth used for method comparison was:

• For the predicate device: A "commercially available immunoassay."
• For the LIAISON® Testosterone xt: "CDC HoSt Testosterone RMP ID-LC-MS/MS values." This is a highly accurate, reference method-based measurement, representing the gold standard for testosterone quantification. Other ground truths were established by controlled experiments for limits (e.g., dilution series for LoB, LoD, LoQ), spiked samples for recovery, and replicated measurements for precision.

8. The Sample Size for the Training Set

The document does not explicitly mention a "training set" in the context of machine learning or AI. This device is an immunoassay, not an AI model that requires a distinct training phase with a labeled dataset in the typical sense. Its development would involve analytical validation using various samples to optimize reagent formulation, assay parameters, and calibration, but not as a machine learning training set.

9. How the Ground Truth for the Training Set was Established

As explained above, there is no "training set" in the machine learning sense for this immunoassay. The development and validation of an immunoassay involve:

• Reference materials: Use of certified reference materials or reference methods (like ID-LC-MS/MS) to establish accurate values for calibrators and controls.
• Spiked samples: Samples with known concentrations of testosterone added.
• Clinical samples: Testing a range of patient samples representing the intended use population, comparing results to established methods.
• Statistical analysis: Extensive statistical methods are used during development and validation to ensure accuracy, precision, linearity, and other performance characteristics.

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The DiaSorin LIAISON® Testosterone assay is a direct, competitive, chemiluminescence immunoassay (CLIA) intended for the quantitative determination of testosterone in human serum and plasma on the LIAISON®Analyzer. The assay is intended for in vitro diagnostic use.

Measurement of testosterone is used in the diagnosis and treatment of disorders involving the male sex hormones (androgens), including primary and secondary hypogonadism, delayed or precocious puberty, impotence in male subjects and, in female subjects hirsutism (excessive hair) and virilization (masculinization) due to tumors, polycystic ovaries, and adrenogenital syndromes.

The DiaSorin LIAISON® Testosterone Control Set is intended for use as assayed quality control samples to monitor the accuracy and precision of the DiaSorin LIAISON® Testosterone immunoassay.

The LIAISON® Testosterone assay's method for quantitative determination of testosterone is a direct, competitive, chemiluminescence immunoassay (CLIA). Specific antibody to testosterone is bound to magnetic particles (solid phase) and testosterone is linked to an isoluminol derivative. During the incubation, testosterone is dissociated from its binding protein and competes with labeled testosterone for binding sites on the antibody. After the incubation, the unbound material is removed with a wash cycle, Subsequently, the starter reagents are added and a flash chemiluminescent reaction is initiated. The light signal is measured by a photomultiplier as relative light units (RLU) and is inversely proportional to the concentration of testosterone present in calibrators, controls, or samples. All assay steps and incubations are performed by the LIAISON® Analvzer.

Two point kit calibrators are used to establish specific working curves based on assay master curves stored on the Analyzer.

The LIAISON® Testosterone reagent kit consists of a reagent intrgral which contains antibody coated magnetic particles (2.3 mL), conjugate (12 mL) and assay buffer (12 mL) reagents. Two levels of ready to use calibrators (2 vials each level, 2.0 mL per vial) are provided with each kit. Each kit consists of 100 tests.

The DiaSorin LIAISON® Testosterone assay and Control Set are subject to a 510(k) premarket notification for substantial equivalence to a predicate device. This submission outlines performance data to demonstrate that the device meets acceptance criteria.

1. Table of Acceptance Criteria and Reported Device Performance:

The document doesn't explicitly state "acceptance criteria" as a separate, defined set of thresholds for each performance metric, but rather presents the results of various studies and compares them to the predicate device and established guidelines (e.g., CLSI guidelines). The performance data implicitly serves as the evidence that the device meets the necessary standards for its intended use.

Here's a summary of the reported device performance:

2. Sample Size Used for the Test Set and the Data Provenance:

• Method Comparison: One hundred eighty-four (184) serum samples were initially tested. One sample was above the upper limit, and 21 samples were below the measuring range of the LIAISON® Testosterone assay and were excluded. Therefore, 162 serum samples were used for the analysis.
  • Data Provenance: Not explicitly stated, but clinical samples (human serum) used to span the reportable range of each assay. Implied to be retrospective as they were collected and then analyzed. The country of origin is not specified.
• Reproducibility/Precision: A coded panel comprised of 6 frozen serum samples (2 low, 2 medium, 2 high) and 2 levels of LIAISON® Testosterone Controls were tested. The total number of measurements for each sample/control across all sites and runs was 480.
  • Data Provenance: DiaSorin Inc. prepared the coded panel. Testing was performed at DiaSorin Inc. and 2 external sites. Implied to be prospective for the purpose of the study. The country of origin is not specified.
• LoB/LoD/LoQ: Sample size not explicitly stated for this particular determination, but it generally involves multiple replicates of blank and low-concentration samples.
  • Data Provenance: Not specified.
• Reference Range/Expected Values:
  • Males 18-49 years: N=161
  • Males ≥ 50 years: N=132
  • Females 18-49 years: N=202
  • Females ≥ 50 years: N=127
  • Data Provenance: Human serum samples from "apparently healthy adults." Implied to be clinical samples, likely prospective for the purpose of establishing reference ranges. The country of origin is not specified.
• Dilution Linearity: Three (3) samples of each sample type (serum, SST serum, EDTA plasma) were used, diluted to span the measuring range.
  • Data Provenance: Not specified.
• Specificity and Interfering Substances: Tested by adding known substances to serum pools. Sample size refers to the number of substances tested rather than individual patient samples.
  • Data Provenance: Not specified.

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 for quantitative determination of a hormone (testosterone). The "ground truth" for such devices is established by reference methods, comparison with predicate devices, and the inherent chemical/biological properties of the analytes. It does not involve human expert interpretation of images or clinical data for individual cases in the same way as, for example, an AI imaging device.

• No "experts" in the sense of clinicians or radiologists establishing ground truth for individual cases are mentioned or relevant for this type of device.
• The ground truth for the method comparison study is implicitly the results obtained from the predicate device, the Roche Cobas® Testosterone II Test (K093421), run on the Elecsys analyzer, which is a previously cleared and accepted method for testosterone measurement.

4. Adjudication Method for the Test Set:

Not applicable. As this is an IVD assay measuring an analyte, there is no adjudication process involving multiple human observers for results. The accuracy is determined by analytical performance against known standards and comparison with accepted methods.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done:

No, an MRMC comparative effectiveness study was not done. This type of study is typically relevant for interpretative devices (e.g., imaging AI) where human readers are making diagnoses. For an IVD assay, the performance is evaluated on its analytical accuracy and precision.

6. If a Standalone (i.e. algorithm only without human-in-the loop performance) Was Done:

Yes, the studies presented (Method Comparison, LoB/LoD/LoQ, Reproducibility/Precision, Dilution Linearity, Specificity, Interfering Substances, Reference Range) all represent the standalone performance of the DiaSorin LIAISON® Testosterone assay without human interpretation or intervention in the measurement process itself, beyond the standard operation of the instrument. The results (e.g., testosterone concentration in ng/dL) are automatically generated by the LIAISON® Analyzer.

7. The Type of Ground Truth Used:

• Method Comparison: The results from the predicate device (Roche Cobas® Testosterone II Test) were used as the reference "ground truth" for comparison.
• Reproducibility/Precision, LoB/LoD/LoQ, Dilution Linearity, Specificity, Interfering Substances: These studies use analytically derived ground truth, often involving:
  • Known concentrations of analytes (e.g., spiked samples for specificity, control materials).
  • Reference materials.
  • Statistical methods to determine limits.
  • Comparison to expected values from dilution series.
• Reference Range/Expected Values: Healthy human serum samples were used to establish the statistical distribution of testosterone in various populations, serving as the "ground truth" for normal physiological ranges.

8. The Sample Size for the Training Set:

This document describes a 510(k) submission for a chemiluminescence immunoassay (CLIA), which is a traditional laboratory-based analytical device, not an AI/Machine Learning model. Therefore, the concept of a "training set" in the context of machine learning is not applicable.

• The assay's "training" or calibration relies on a master curve stored on the Analyzer and specific working curves established with two-point kit calibrators provided with each kit. These calibrators contain known concentrations of testosterone.

9. How the Ground Truth for the Training Set Was Established:

As noted above, this is not an AI/ML device, so there is no "training set" in that sense. The "ground truth" for the calibrators (which are analogous to the data used to "train" a traditional assay) is established through:

• Manufacturing and Analytical Certification: Calibrators are precisely manufactured with known, certified concentrations of testosterone. These concentrations are typically determined using highly accurate reference methods (e.g., isotope dilution mass spectrometry - ID-MS), which serve as the gold standard for analyte quantification.
• Master Curves: The assay relies on a "master curve" stored on the LIAISON® Analyzer. This master curve is developed using a comprehensive set of reference materials with certified testosterone concentrations to define the relationship between the signal (RLU) and the analyte concentration across the entire measuring range. The two-point calibrators then adjust this master curve for each specific kit and run to account for minor variations.

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