(47 days)
Syntron's QuikPac II One Step Phencyclidine (PCP) assay is a rapid, qualitative, competitive binding immunoassay for the determination of Phencyclidine (PCP) in urine at the cutoff level of 25 ng/ml. The test provides only preliminary data which should be confirmed by other methods such as gas chromatography/mass spectrophotometry (GC/MS). Clinical considerations and professional judgment should be applied to any drug of abuse test result, particularly when preliminary positive results are indicated6. Syntron's QuikPac II One Step Phencyclidine (PCP) Test is not intended to monitor drug levels, but only to screen urines for the presence of Phencyclidine (PCP) and its metabolites.
Syntron's QuikPac II One Step Phencyclidine (PCP) Test consists of a chromatographic absorbent device in which the drug or drug metabolites in the sample compete with a drug conjugate immobilized on a porous membrane support for the limited antibody sites. As the test sample flows through the absorbent device, the labeled antibody-dye conjugate binds to the free drug in the specimen forming an antibody:antigen complex. This complex competes with immobilized antigen conjugate in the positive reaction zone and will not produce a magenta color band when the drug is above the detection level of 25 ng/ml. Unbound dye conjugate binds to the reagent in the control zone, producing a magenta color band, demonstrating that the reagents and device are functioning correctly.
Here's a breakdown of the acceptance criteria and study information for the QuikPac II One Step Phencyclidine Test, based on the provided text:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Device Performance (In-house Testing) | Device Performance (Clinical Trial) |
|---|---|---|
| Relative Specificity | 1.00 (100%) | 100% |
| Relative Sensitivity | 1.00 (100%) | (Not explicitly stated as "relative sensitivity", but 100% agreement within positive samples is implied given 100% accuracy and specificity) |
| Accuracy | 100% | 100% |
| False Positives | (Not stated explicitly for in-house) | 2 |
| False Negatives | (Not stated explicitly for in-house) | 0 |
Note: The reported performance metrics for the clinical trial (agreement within positive samples and agreement within negative samples) are equivalent to relative sensitivity and relative specificity, respectively. "Agreement within positive samples" of 100% means no false negatives relative to the comparator. "Agreement within negative samples" of 100% means no false positives relative to the comparator. The overall accuracy of 100% further supports these interpretations.
Study Details:
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Sample size used for the test set and the data provenance:
- In-house testing: 227 samples. Data provenance is not specified beyond "in-house testing" by Syntron Bioresearch, Inc. It's likely retrospective data collected from an internal or readily available sample set.
- Clinical trial: 286 samples. Data provenance is not specified beyond stating it was a "clinical trial" and "the Clinical Trial site" was involved. It is implied to be prospective collection for the purpose of the trial. Country of origin is not mentioned.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This information is not provided for either the in-house testing or the clinical trial. The ground truth was established by comparison to the Syva EMIT® IIm device and confirmed by GC/MS. The expertise of those performing the EMIT II or GC/MS analysis is not detailed.
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Adjudication method for the test set:
- Not applicable in the traditional sense of human readers/experts adjudicating cases. The comparison was against objective reference methods (Syva EMIT® IIm and GC/MS). Discrepancies were resolved by GC/MS.
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If a multi-reader multi-case (MRMC) comparative effectiveness study was done:
- No, an MRMC study was not done. This device is an in-vitro diagnostic test, not an imaging or interpretive device that typically involves human readers.
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If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
- Yes, this was a standalone performance study. The QuikPac II test is a rapid, qualitative immunoassay that provides a visible color band result. Its performance was evaluated directly without human interpretation influencing the test result itself, although a human is required to observe and record the presence or absence of the color band. The comparison methods (EMIT II and GC/MS) are also standalone laboratory tests.
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The type of ground truth used:
- The primary ground truth for initial comparison was the Syva EMIT® IIm.
- For discrepancies and confirmation, Gas Chromatography/Mass Spectrophotometry (GC/MS) was used as the confirmatory gold standard. The text explicitly states, "All positive samples by either screening method were confirmed by GC/MScs."
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The sample size for the training set:
- This information is not explicitly provided. The described testing refers to verification and validation on "test sets" (in-house and clinical trial samples). As this is a chemical assay, rather than a machine learning algorithm, the concept of a "training set" for an algorithm's learning phase is not directly applicable. The device's formulation and manufacturing would have been developed and refined through R&D, but specific "training set" sizes are not reported in this context.
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How the ground truth for the training set was established:
- Not applicable / Not provided as per the explanation above regarding "training set". The development of the assay's reagents and mechanics would have relied on established biochemical principles and extensive internal testing against known concentration standards and spiked samples to achieve the desired cutoff and specificity, but this is not termed a "training set" in the context of an immunoassay.
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