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The AMDL-ELISA DR-70® (FDP) immunoassay is designed for IN VITRO DIAGNOSTIC USE ONLY for the quantitative measurement of DR-70® (FDP) in human serum. Serial testing using the AMDL- ELISA DR-70® (FDP) is to be used as an aid in monitoring the disease progression in patients who have been diagnosed previously with colorectal cancer. Results of DR-70® (FDP) testing should be used in conjunction with other clinical modalities that are standard of care for monitoring disease progression in these patients.

The AMDL, Inc. DR-70® (FDP) assay is an ELISA based assay utilizing removable strips in a 96 micro titer plate well format. The wells are coated with affinity purified rabbit anti-DR-70® (FDP) antibodies. The DR-70® (FDP) in diluted sera (1:200) is captured from the sera by these antibodies immobilized on the well of a micro titer plate. After a wash step, anti-DR-70® (FDP) antibodies conjugated to horseradish peroxidase are added to the wells. If the DR-70® (FDP) antigen is present, the anti-human fibrinogen peroxidase complex will bind to the captured tumor marker to form an immunological sandwich with the immobilized antibodies. After a second wash step, the enzyme substrate 3,3',5'-tetramethylbenzidine (TMB) is added to the well. The end point is read in a micro plate reader at 450 nm once the reaction is stopped with 0.1N HCl. The intensity of the color formed is proportional to the amount of DR-70® (FDP) in the serum. The amount is quantified by interpolation from a standard curve using the calibrators provided with the kit.

Here's a summary of the acceptance criteria and the study that proves the device meets them, based on the provided text:

Device: AMDL-ELISA DR-70® (FDP)

Intended Use: For IN VITRO DIAGNOSTIC USE ONLY for the quantitative measurement of DR-70® (FDP) in human serum. Serial testing using the AMDL-ELISA DR-70® (FDP) is to be used as an aid in monitoring the disease progression in patients who have been diagnosed previously with colorectal cancer. Results of DR-70® (FDP) testing should be used in conjunction with other clinical modalities that are standard of care for monitoring disease progression in these patients.

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state "acceptance criteria" in a table format. Instead, it presents various performance characteristics and concludes that the device is "informative" for monitoring disease progression in colorectal cancer and supports a finding of substantial equivalence. For this table, I will use the established performance metrics as the defacto "acceptance criteria" through their demonstration of "informativeness" or adequate performance for the intended use in comparison to a predicate device and clinical status.

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

• Test Set Description: "retrospective blood samples collected prospectively"

• Data Provenance: Not explicitly stated, but the submission is to the US FDA, implying clinical studies conducted in a manner acceptable for US regulatory review.

• Sample Size for Clinical Informativeness Study:

  • Patients: 112 colon cancer patients.
  • Serial Observations: 446 paired observations (DR-70 reading and disease progression determination).
  • Post-baseline paired observations for analysis: 335.
  • Visits for Sensitivity Analysis: 135.
  • Visits for Specificity Analysis: 198.
  • Patients with at least one sensitivity, specificity, or both: 112 patients.
  • Estimated per-patient sensitivity: 70 estimates.
  • Estimated per-patient specificity: 86 estimates.

• Sample Sizes for Distribution of DR-70® (FDP) values (used for establishing reference ranges/disease cohorts):

  • Normal: 420 (337 < 65 years, 83 > 65 years)
  • Benign: 326 (94 GU Disease, 61 GI Disease, 84 Pancreas, 87 Heart Disease)
  • Malignant: 439 (187 Colon, 44 Lung, 44 Liver, 31 Breast, 31 Ovarian, 28 Cervical, 19 Gall Bladder, 28 Pancreas, 27 Gastric/Other)

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

• The ground truth for the clinical study was established based on "clinical impressions of the treating physicians based on Subject interviews, physical examination, laboratory results, X-rays, CAT scans and MRI as they are used in routine clinical practice in managing colorectal cancer Subjects."
• Number of Experts: Not specified. It refers to "treating physicians" (plural), implying multiple physicians were involved across the patient cohort.
• Qualifications of Experts: Assumed to be qualified physicians specializing in the management of colorectal cancer, given they are "treating physicians" and using standard clinical modalities. Specific years of experience or board certifications are not detailed in the provided text.

4. Adjudication Method for the Test Set

• The ground truth relied on "clinical impressions of the treating physicians" using a combination of standard clinical modalities. However, the document does not specify a formal adjudication method (e.g., 2+1, 3+1 consensus). It appears to accept the treating physician's integrated clinical assessment as the ground truth.

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

• No, a MRMC comparative effectiveness study was not done in the context of human readers using/not using AI assistance. This device is an in vitro diagnostic (IVD) immunoassay, not an AI imaging device or decision support system for human readers. The study evaluates the performance of the immunoassay itself.

6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done

• Yes, a standalone performance study was done. The entire clinical study described evaluates the AMDL-ELISA DR-70® (FDP) immunoassay as a standalone diagnostic tool. Its results (DR-70® FDP concentration changes) are directly compared to the clinical disease status (the ground truth). The statement "The DR-70® (FDP) immunoassay results must be used in conjunction with standard of care procedures" indicates that it is intended to augment, rather than replace, clinical judgment, but its performance was assessed independently against clinical outcomes.

7. The Type of Ground Truth Used

• Clinical Ground Truth: The ground truth for the clinical informativeness study was derived from "clinical impressions of the treating physicians based on Subject interviews, physical examination, laboratory results, X-rays, CAT scans and MRI as they are used in routine clinical practice in managing colorectal cancer Subjects."
• For the initial cohort distribution studies (Normal, Benign, Malignant), the ground truth was the established diagnosis of the subjects enrolling in those cohorts.

8. The Sample Size for the Training Set

• The document describes a "clinical trial using retrospective blood samples collected prospectively" that served as the test set. It does not explicitly mention a separate "training set" for the immunoassy itself in the context of machine learning, as this is a biochemical assay.
• The "training" (or rather, development) of the assay would involve various analytical performance studies (recovery, linearity, precision, etc.) and the establishment of assay parameters (e.g., standard curve, cut-offs), which are described as "Performance Testing." These involve internal experiments rather than a distinct 'training set' of clinical data for an algorithm.

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

• As noted above, for an immunoassay, the concept of a "training set" and associated "ground truth" for machine learning is not directly applicable. The "ground truth" for developing and validating the analytical performance of the immunoassay (e.g., calibrator values for recovery, known concentrations for linearity and sensitivity) would be established through laboratory standards, spiked samples with known concentrations, and internal controls according to standard laboratory practices.
• The normal, benign, and malignant disease cohorts in the clinical study helped establish the clinical context and distribution of DR-70 values, which informs clinical interpretation rather than directly "training" an algorithm in the machine learning sense. The ground truth for these cohorts was their clinical diagnosis.

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PyloriProbe™ is an ELISA test intended for the qualitative detection of serum IgG antibodies to H. pylori as an aid in the diagnosis of H. pylori infection in adult patients with gastrointestinal symptoms. The test is not to be used with asymptomatic patients. The tests are carried out in clinical laboratories by laboratory technologists / technicians and the test results are measured in a microtiter plate reader instrument.

PyloriProbe™ is an ELISA test intended for the qualitative detection of serum IgG antibodies to H. pylori.

This FDA letter for K981396, "PyloriProbeTM," does not contain the detailed information necessary to answer the questions about acceptance criteria and the study proving device performance as typically expected for medical device submissions. This letter is a 510(k) clearance, which confirms substantial equivalence to a predicate device, rather than a full review of a new clinical study.

Therefore, many of the requested details are not available in the provided document.

However, based on the information present, here's what can be extracted and noted regarding the lack of other information:

1. A table of acceptance criteria and the reported device performance

• Not Available. The document is a 510(k) clearance letter and does not include performance data or specific acceptance criteria. It only states that the device is "substantially equivalent" to legally marketed predicate devices.

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

• Not Available. The document does not provide details about a test set sample size or its provenance.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

• Not Available. The document does not describe the establishment of a ground truth for a test set or the involvement of experts in that process.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

• Not Available. The document does not mention any adjudication methods for a test set.

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 / Not Available. The PyloriProbeTM is an ELISA test for the detection of H. pylori antibodies, not an AI-assisted diagnostic imaging or interpretation device. Therefore, an MRMC study with AI assistance is not relevant to this device type. The document does not mention any comparative effectiveness studies.

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

• Not Applicable / Not Available. This device is an in vitro diagnostic (IVD) ELISA test that is performed and interpreted by laboratory technologists/technicians. It is not an algorithm-only device. The document does not detail performance studies for the device.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

• Not Available. The document does not specify the type of ground truth used for any performance evaluation. For an IVD like this, ground truth would typically be established through other definitive diagnostic methods for H. pylori infection (e.g., biopsy, culture, urea breath test) against which the ELISA results are compared.

8. The sample size for the training set

• Not Available. The document does not provide information about a training set since this is a 510(k) clearance for an IVD test, not a submission for an AI/machine learning model.

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

• Not Available. As above, no training set is discussed or implied by the document's content.

In summary, the provided FDA 510(k) clearance letter focuses on the regulatory determination of substantial equivalence rather than on detailed performance study results that would contain the requested information. To find such details, one would typically need to review the full 510(k) submission summary or detailed results from the manufacturer (AMDL, Inc.).

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