(290 days)
The CEDIA® Phencyclidine (PCP) OFT Assay is intended for use in the qualitative determination of phencyclidine in human oral fluid at a cutoff concentration of 3 ng/mL in neat oral fluid. The specimen must be collected exclusively with the Oral-Eze™ Saliva Collection System. The assay is calibrated against PCP and performed on the MGC 240. This in vitro diagnostic device is intended for clinical laboratory use only.
The CEDIA Phencyclidine (PCP) OFT Assay provides only a preliminary analytical test result. A more specific alternative method must be used to obtain a confirmed analytical result. Gas Chromatography/Mass Spectrometry (GC/MS) and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) are the preferred confirmatory methods. Clinical consideration and professional judgment should be applied to any drug of abuse test result particularly when preliminary positive results are used.
Microgenics CEDIA® PCP OFT Assay uses recombinant DNA technology to produce a unique homogeneous enzyme immunoassay system. The assay is based on the bacterial enzyme β-galactosidase, which has been genetically engineered into two inactive fragments. These fragments spontaneously re-associate to form fully active enzyme that, in the assay format, cleave a substrate, generating a color change that can be measured spectrophotometrically.
Here's an analysis of the provided text regarding the acceptance criteria and study for the CEDIA® Phencyclidine (PCP) OFT Assay:
1. Table of Acceptance Criteria and Reported Device Performance:
The document doesn't explicitly state quantitative acceptance criteria (e.g., "sensitivity must be >95%"). Instead, it describes performance in qualitative terms. However, based on the stated "Method Comparison" results, we can infer the implicit acceptance criteria that the device should demonstrate high concordance, sensitivity, and specificity with a confirmed method.
| Acceptance Criteria (Inferred from study results) | Reported Device Performance (CEDIA® PCP OFT Assay) |
|---|---|
| Accurate recovery of samples below cutoff (negative) | All samples below cutoff read as negative. |
| Accurate recovery of samples above cutoff (positive) | All samples above cutoff read as positive. |
| Accurate recovery of low control (negative) | Low control read as negative. |
| Accurate recovery of high control (positive) | High control read as positive. |
| No significant interference from endogenous/exogenous substances | No significant interference observed. |
| No significant cross-reactivity with unrelated compounds | No significant cross-reactivity observed. |
| High overall concordance with GC/MS or LC-MS/MS | 100.0 % concordance with GC/MS. |
| High sensitivity compared to GC/MS or LC-MS/MS | 100.0 % sensitivity to GC/MS. |
| High specificity compared to GC/MS or LC-MS/MS | 100.0 % specificity to GC/MS. |
2. Sample Size Used for the Test Set and Data Provenance:
The document does not explicitly state the sample size used for the test set in the "Method Comparison" study that determined 100% concordance, sensitivity, and specificity. It also does not specify the country of origin for the data or whether it was retrospective or prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications:
The document does not mention the use of human experts to establish ground truth for the test set. Instead, the ground truth was established by confirmatory analytical methods (GC/MS).
4. Adjudication Method for the Test Set:
Not applicable. The ground truth was established through analytical methods (GC/MS), not through expert review requiring adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of How Much Human Readers Improve with AI vs Without AI Assistance:
Not applicable. This device is an in vitro diagnostic assay, not an AI-assisted diagnostic tool for human readers. Therefore, an MRMC study and analysis of human reader improvement with AI assistance are not relevant.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:
Yes, the studies presented are standalone performance evaluations of the assay itself. The "Method Comparison" directly compares the device's output to the gold standard (GC/MS) without human interpretation as an intermediate step.
7. The Type of Ground Truth Used:
The ground truth used for the "Method Comparison" study was Gas Chromatography/Mass Spectrometry (GC/MS). The document also mentions Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) as an alternative preferred confirmatory method.
8. The Sample Size for the Training Set:
The document does not explicitly state the sample size used for any training set. This is typical for an immunoassay, as it's not a machine learning model that undergoes explicit "training" on a dataset in the same way. The assay's performance is established through analytical validation studies on samples.
9. How the Ground Truth for the Training Set Was Established:
Not applicable in the context of "training set" for a machine learning model. For the assay's development and validation, the ground truth for samples used in analytical studies (e.g., precision, cutoff characterization, interference, specificity) would have been established through controlled spiking of known concentrations or independent confirmatory methods such as GC/MS for validation of spiked samples. The document implies that the assay was calibrated against PCP.
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