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This is an immunochromatographic assay for the simultaneous qualitative detection and distinguishing of Giardia and Cryptosporidium specific antigens in aqueous extracts of fecal specimens.

It is intended for professional laboratory use.

For In Vitro Diagnostic Use.

Immunoassay for Giardia and Cryptosporidium Antigens

Here's a breakdown of the acceptance criteria and study details for the Genzyme Contrast® Giardia/Cryptosporidium Combo Rapid Assay:

Acceptance Criteria and Reported Device Performance

Note: The document does not explicitly state numerical acceptance criteria thresholds like "Sensitivity > 95%". Instead, the performance is presented as the outcome of the study, implying that the observed high sensitivity and specificity values were considered acceptable for demonstrating substantial equivalence. The precision studies explicitly state 100% agreement as the specification.

Study Details

1. Sample Size used for the test set and the data provenance:

   • Retrospective Analysis vs Microscopic Examination:
     • Giardia: 33 positive, 109 negative (total 142)
     • Cryptosporidium: 37 positive, 105 negative (total 142)
   • Prospective Analysis vs Microscopic Examination:
     • Giardia: 50 positive, 452 negative (total 502)
     • Cryptosporidium: 73 positive, 429 negative (total 502)
   • Retrospective Analysis vs Rapid EIA (Predicate):
     • Giardia: 142 samples (agreement reported for 138/142)
     • Cryptosporidium: 142 samples (agreement reported for 142/142)
   • Provenance: The document does not explicitly state the country of origin. Both "Retrospective Analysis" and "Prospective Analysis" are mentioned, indicating a mix of historical and newly collected samples for the microscopic comparison. The comparison against the predicate EIA is stated as "Retrospective Analysis."

2. 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 or qualifications of experts. Ground truth was established by "microscopic examination," which is typically performed by trained laboratory personnel (e.g., medical technologists or microbiologists) but no specific expert details are provided.

3. Adjudication method for the test set:

   • The document does not specify any adjudication method (e.g., 2+1, 3+1). It simply states "microscopic examination" as the reference method, implying a single definitive read or a standard laboratory process.

4. 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:

   • No. This study is for an in vitro diagnostic (IVD) assay, not an AI-assisted device for human readers. Therefore, an MRMC comparative effectiveness study comparing human readers with and without AI assistance is not applicable and was not performed.

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

   • Yes, effectively. The "Genzyme Giardia/Cryptosporidium Assay" performance (sensitivity and specificity) is reported as a standalone device performance when compared against the reference method (microscopic examination) and the predicate method (Alexon ProSpecT). As an IVD, it is essentially an "algorithm only" in the sense that the assay itself produces the result, without direct human cognitive input to interpret an image or signal beyond reading the immunoassay result.

6. The type of ground truth used:

   • Expert Consensus / Reference Method: "Microscopic examination" is stated as the "Reference method." This implies that microscopic identification of Giardia and Cryptosporidium organisms in fecal samples serves as the gold standard for establishing the ground truth.

7. The sample size for the training set:

   • The document does not provide any information regarding a training set sample size. This is typical for traditional IVD assays, where method development and optimization (analogous to training) involve internal studies and reagent formulation, which are distinct from the formal clinical performance studies presented here.

8. How the ground truth for the training set was established:

   • As no training set is explicitly mentioned or detailed, there is no information provided on how its ground truth was established.

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