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The Solana® Trichomonas Assay is an in vitro diagnostic test, using isothermal amplification technology (helicase-dependent amplification, HDA), for the qualitative detection of Trichomonas vaginalis nucleic acids isolated from clinician-collected vaginal swabs and female urine specimens obtained from symptomatic females to aid in the diagnosis of trichomoniasis. The Solana® Trichomonas Assay is intended for use only with the Solana® instrument.

The Solana® Trichomonas Assay amplifies and detects Trichomonas vaginalis nucleic acids present in clinician-collected vaginal swabs and urine specimens from symptomatic and asymptomatic women. The assay targets a conserved multi-copy sequence of the T. vaqinalis DNA. The vaginal swab is eluted in a swab lysis tube or a urine specimen is added to a urine lysis tube, and the cells in either specimen type are lysed by simple heat treatment. After heat treatment, an aliquot of the lysed specimen is transferred into a dilution tube. An aliquot of the diluted sample is added to a reaction tube. The Reaction Tube contains lyophilized HDA reagents, dNTPs, primers and probes. Once rehydrated with the diluted sample, the Reaction Tube is placed in Solana for amplification and detection of T. vaginalis-specific target sequence. In Solana, the target sequence is amplified by T. vaginalis specific primers and detected by a T. vaginalis specific fluorescence probe included in the Reaction Tube. A competitive process control (PRC) is included in the Lysis Tube to monitor sample processing, inhibitory substances in clinical samples, reagent failure or device failure. The PRC target is amplified by T. vaginalis specific primers and detected by a PRC specific fluorescence probe. The target and PRC probes are labeled with a quencher on one end and a fluorophore on the other end. In addition, the target and PRC probes carry a ribonucleic acid. Upon annealing to T. vaqinalis or PRC amplicons, the fluorescence probes are cleaved by RNaseH2 and the fluorescence signal increases due to physical separation of fluorophore from quencher. Solana measures and interprets the fluorescent signal, using on-board method-specific algorithms. Solana instrument will then report the test results to the user on its display screen, and the results can be printed via a printer.

Here's an analysis of the provided text, focusing on acceptance criteria and study details for the Solana® Trichomonas Assay:

Executive Summary:

The Solana® Trichomonas Assay is an in vitro diagnostic test for the qualitative detection of Trichomonas vaginalis using isothermal amplification technology (HDA). The device was evaluated in a multi-center clinical study comparing its performance against a composite reference method (Wet Mount and InPouch TV Culture) for both vaginal swab and urine specimens. The study included symptomatic and asymptomatic female patients.

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state pre-defined "acceptance criteria" as distinct numerical targets that the FDA required the device to meet for approval. Instead, it presents the "Performance Characteristics" from the clinical study, which are then used to demonstrate substantial equivalence to a predicate device. The comparison table below uses the clinical study results as "reported device performance."

Note: The predicate device comparison table focuses on "Performance Characteristics" as opposed to explicit numerical acceptance criteria. The sensitivity and specificity values observed in the clinical trial would implicitly serve as the benchmark for demonstrating that the device performs as intended and is as safe and effective as the predicate device.

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

• Sample Size for Test Set:
  • Vaginal Swabs: 1043 subjects (after re-testing of invalid results).
  • Female Urine Specimens: 1044 subjects (after re-testing of invalid results).
  • Reproducibility Study (Analytical Performance): 90 samples per category per workflow (swab/urine) across 3 sites (e.g., 90 Low Positive swab samples, 90 Negative swab samples, etc.). This totals to 540 swab samples and 540 urine samples for reproducibility.
• Data Provenance:
  • Country of Origin: United States
  • Retrospective or Prospective: Prospective. The clinical study was performed from November 2015 through March 2016, and specimens were obtained from each subject after informed consent.

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

The document does not specify the number of experts or their qualifications used to establish the ground truth beyond stating that the reference methods for the clinical study were "Wet Mount" and "InPouch TV Culture." These are laboratory-based diagnostic tests, typically performed by trained medical technologists or laboratory personnel, not necessarily "experts" in the sense of physicians or specialists establishing a consensus diagnosis.

4. Adjudication Method for the Test Set

• Clinical Study: The adjudication method for the clinical study was based on a composite reference method. A specimen was considered positive if either the Wet Mount or the InPouch TV Culture was positive.
• Discordant Analysis: For specimens where the Solana Assay results differed from the composite reference method, an FDA-cleared Trichomonas vaginalis molecular assay was used for further testing (referred to as "discordant testing").

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

• No, a MRMC comparative effectiveness study was not explicitly mentioned or performed in the context of human readers improving with AI vs. without AI assistance. This device is a diagnostic assay (an in vitro diagnostic test) that provides qualitative results directly, not an AI-assisted interpretation by human readers. The clinical study evaluated the device's standalone performance compared to established clinical reference methods.

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

• Yes, a standalone performance evaluation was done. The Solana® Trichomonas Assay is an automated in vitro diagnostic test that uses "on-board method-specific algorithms" to measure and interpret fluorescent signals and report test results. The clinical study assessed the performance of this device as an algorithm-only system against the composite reference methods.

7. The Type of Ground Truth Used

• Clinical Study: The ground truth for the clinical study was established using a composite reference method consisting of:
  • Wet Mount
  • InPouch TV Culture
    A specimen was considered positive if either of these reference tests was positive.
• Analytical Sensitivity (LoD) and Inclusivity Studies: Ground truth was based on quantified strains of T. vaginalis (trophozoite/mL) at known concentrations.

8. The Sample Size for the Training Set

• The document does not specify a separate "training set" sample size for the Solana® Trichomonas Assay. This is typical for in vitro diagnostic assays of this nature, where the "training" (development and optimization) of the assay's reagents and algorithms is usually an iterative laboratory process, not based on a distinct clinical training dataset to the same extent as, for example, a machine learning algorithm for image analysis. The clinical evaluation primarily serves as a validation set.

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

• As mentioned above, a distinct "training set" with established ground truth in a clinical context is not explicitly described.
• For analytical studies (e.g., LoD, inclusivity): Ground truth was established by using quantified strains of T. vaginalis at known concentrations (e.g., trophozoite/mL) diluted in negative clinical matrix. These known concentrations serve as the "ground truth" for evaluating analytical performance parameters. Development and optimization of the assay would rely on such controlled laboratory experiments.

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