(136 days)
The ARCHITECT 2nd Generation Testosterone assay is a chemiluminescent microparticle immunoassay (CMIA) for the quantitative determination of testosterone in human serum and plasma.
Measurements of testosterone are 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) due to tumors, polycystic ovaries, and adrenogenital syndromes.
The ARCHITECT 2nd Generation Testosterone assay is a delayed one-step immunoassay for the quantitative determination of testosterone in human serum and plasma using chemiluminescent microparticle immunoassay (CMIA) technology with flexible assay protocols, referred to as Chemiflex.
In the first step, sample, assay specific diluent, and anti-testosterone (sheep, monoclonal) coated paramagnetic microparticles are combined. Testosterone present in the sample binds to the anti-testosterone coated microparticles. After incubation, testosterone acridinium-labeled conjugate is added to the reaction mixture. After further incubation and washing, pre-trigger and trigger solutions are added to the reaction mixture. The resulting chemiluminescent reaction is measured as relative light units (RLUs). An inverse relationship exists between the amount of testosterone in the sample and the RLUs detected by the ARCHITECT i System optics. The concentration of testosterone is interpolated from a calibration curve established with calibrators of known testosterone concentration.
The provided text is related to the Abbott Laboratories ARCHITECT 2nd Generation Testosterone assay (K152155). This 510(k) summary is for a labeling change to include Free Testosterone Index (FTI) or Free Androgen Index (FAI) expected values, not for a new device or a change in the device's fundamental performance. Therefore, the information typically requested in questions 1-9 for device performance and acceptance criteria is not directly applicable to this submission, as the core assay performance data was established in the prior clearance (K120009).
However, I can extract information related to the newly included FTI/FAI expected values study and how it was conducted, aligning it as much as possible with your request structure.
Here's a breakdown based on the provided text, focusing on the FTI/FAI study:
1. A table of acceptance criteria and the reported device performance
- Acceptance Criteria: The document does not explicitly state formal acceptance criteria (e.g., specific thresholds for accuracy, precision) for the FTI/FAI expected values study. The study's purpose was to calculate and summarize expected values for different demographic groups. The implicit acceptance was that the calculated FTI/FAI ranges would be provided in the labeling.
- Reported Device Performance (FTI/FAI Expected Values):
| Category | N | Median (%) | 2.5th Percentile (%) | 97.5th Percentile (%) |
|---|---|---|---|---|
| Males (21-49 years of age) | 163 | 46.6 | 24.5 | 113.3 |
| Males (≥ 50 years of age) | 144 | 40.7 | 19.3 | 118.4 |
| Females (Premenopausal, 21-49 years of age) | 174 | 2.0 | 0.7 | 8.7 |
| Females (Postmenopausal, ≥ 50 years of age) | 175 | 1.5 | 0.5 | 4.7 |
2. Sample size used for the test set and the data provenance
- Sample Size for the FTI/FAI Study (effectively the test set for new expected values):
- Normal males 21-49 years of age: N=163
- Normal males ≥ 50 years of age: N=144
- Premenopausal normal females 21-49 years of age: N=174
- Postmenopausal normal females ≥ 50 years of age: N=175
- Total N = 556
- Data Provenance: The document does not explicitly state the country of origin. It indicates the study was conducted in 2014. It is an internal study by Abbott, likely involving prospective sample collection for the purpose of establishing these expected values, as described by the "inclusion/exclusion criteria."
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Not applicable. For in vitro diagnostic assays measuring specific analytes like Testosterone and SHBG, the "ground truth" for the test set is established by the assay's quantitative measurement itself, not by expert interpretation of images or clinical data. The FTI/FAI are calculated from these quantitative measurements. The classification of individuals into "normal males/females" etc., would have followed standard clinical criteria, but no "experts" for ground truth establishment in the traditional sense (e.g., radiologist consensus) are mentioned or typically used for this type of IVD study.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not applicable. Adjudication methods are typically used in studies involving subjective interpretation (e.g., image reading) where multiple readers disagree. This is a quantitative assay study where numerical results are generated and then used to calculate an index.
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 submission is for an in vitro diagnostic (IVD) assay, not an AI-assisted diagnostic tool. No human reader performance improvement is relevant.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Yes, in essence. The ARCHITECT 2nd Generation Testosterone assay (and ARCHITECT SHBG assay) operate as standalone automated systems. The performance data for the core assays (which were part of K120009 and are referenced as still applying) represent the algorithm's (instrument's) performance in quantifying testosterone and SHBG. The FTI/FAI itself is a calculation based on these standalone measurements.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- For the FTI/FAI study, the "ground truth" for each individual sample's testosterone and SHBG levels was the quantitative result provided by the ARCHITECT 2nd Generation Testosterone assay and the ARCHITECT SHBG assay, respectively. These assays are designed to directly measure the analyte concentration. The classification of individuals into demographic groups (e.g., "normal males," "premenopausal females") would rely on self-reported data and/or clinical assessment to ensure they fit the "normal" criteria used for establishing expected values.
8. The sample size for the training set
- Not explicitly stated as a separate "training set" for the FTI/FAI expected values study. The study described (with N=556 across categories) generated the expected values directly. For the original ARCHITECT 2nd Generation Testosterone assay (K120009), there would have been extensive datasets used for calibration and method development, but those details are not in this document. This specific submission focuses on new expected values based on a defined cohort.
9. How the ground truth for the training set was established
- As above, for the FTI/FAI expected values study, the ground truth was based on the quantitative results from the ARCHITECT Testosterone and SHBG assays. The samples were selected based on inclusion/exclusion criteria to represent "normal" populations for each demographic. For the original assay development (K120009), ground truth would typically involve comparison to reference methods, established standards, and clinical samples of known concentrations, but those specifics are outside the scope of this particular 510(k) summary.
§ 862.1680 Testosterone test system.
(a)
Identification. A testosterone test system is a device intended to measure testosterone (a male sex hormone) in serum, plasma, and urine. Measurement of testosterone are 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.(b)
Classification. Class I.