(83 days)
Wondfo Propoxyphene Urine Test is an immunochromatographic assay for the qualitative determination of d-Propoxyphene in human urine at a cutoff concentration of 300 ng/mL. The test is available in a dip card format and a test cup format. It is intended for prescription use and over the counter use. The test provides only preliminary test results. A more specific alternative chemical must be used in order to obtain a confirmed analytical result. GC/MS is the preferred confirmatory method. The test will yield preliminary positive results when prescription drug d-Propoxyphene is ingested, even at or above therapentic doses. There is no uniformly recognized cutoff concentration for d-Propoxyphene. It is not intended to distinguish between prescription use or abuse of this drug. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary result is positive.
The Wondfo Propoxyphene Urine Test uses immunochromatographic assays for d-Propoxyphene. The test is a lateral flow system for the qualitative detection of d-Propoxyphene in human urine. The test is the first step in a two-step process. The second step is to send the sample for laboratory testing if preliminary positive results are obtained.
Here's a breakdown of the acceptance criteria and study information for the Wondfo Propoxyphene Urine Test devices, as extracted from the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document primarily focuses on a "Lay-user study" for establishing performance in the context of an OTC claim addition. The acceptance criteria for this study are implied by the desired percentage of correct results for various d-Propoxyphene concentrations relative to the 300 ng/mL cutoff. While explicit numerical acceptance criteria (e.g., "must achieve X% accuracy") are not stated, the study demonstrates desired performance.
| Urine Sample Concentration (% of Cutoff) | d-Propoxyphene Concentration by GC/MS (ng/mL) | Acceptance Criteria (Implied: High % Correct) | Reported Device Performance - Cup Format (% Correct Results by Lay Person) | Reported Device Performance - DipCard Format (% Correct Results by Lay Person) |
|---|---|---|---|---|
| -100% of Cutoff (0 ng/mL) | 0 | 100% Negative | 100% | 100% |
| -75% of Cutoff | 75.6 | 100% Negative | 100% | 100% |
| -50% of Cutoff | 148.3 | 100% Negative | 100% | 100% |
| -25% of Cutoff | 226.7 | High % Negative (e.g., >90%) | 90.0% | 90.0% |
| +25% of Cutoff | 378.2 | High % Positive (e.g., >90%) | 90.0% | 90.0% |
| +50% of Cutoff | 452.4 | 100% Positive | 100% | 100% |
| +75% of Cutoff | 523.1 | 100% Positive | 100% | 100% |
2. Sample Sizes Used for the Test Set and Data Provenance
- Sample Size for Test Set:
- Lay-user study: 280 lay persons in total, with 140 testing the cup format and 140 testing the dip card format. Each lay person tested one blind-labeled sample.
- For each concentration level represented in the table above, there were 20 samples for the cup format and 20 samples for the dip card format.
- Data Provenance: The document does not explicitly state the country of origin for the data or if it was retrospective or prospective. Given that the submitter is Guangzhou Wondfo Biotech Co., Ltd. from China, and the study was performed "at three intended user sites," it's likely the samples and study were conducted in China, and it appears to be a prospective study designed for this submission.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Number of Experts: Not applicable in the context of expert review for ground truth in this lay-user study.
- Qualifications of Experts: Not applicable.
4. Adjudication Method for the Test Set
- Adjudication Method: Not applicable. The "ground truth" was established independently by GC/MS and then compared directly to the lay user's interpretation.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
- MRMC Study: No, an MRMC comparative effectiveness study was not explicitly mentioned or performed in the provided text. The study described is a lay-user study comparing the device's output (as interpreted by lay users) against a gold standard (GC/MS).
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
- Standalone Performance: The Wondfo Propoxyphene Urine Test is an immunochromatographic assay, which is a rapid diagnostic test interpreted by a human. Therefore, the concept of a "standalone algorithm" doesn't directly apply in the same way it would for a digital imaging AI device. The lay user study is a test of human-in-the-loop performance, where the human interprets the result of the assay. The results for the cup and dip card formats are reflective of the final human-interpreted output.
7. The Type of Ground Truth Used
- Type of Ground Truth: The ground truth for the test samples was established by Gas Chromatography/Mass Spectrometry (GC/MS). The document states: "The concentrations of the samples were confirmed by GC/MS."
8. The Sample Size for the Training Set
- Sample Size for Training Set: The document does not describe a distinct "training set" in the context of machine learning. The device is an immunochromatographic assay, not an AI/ML algorithm that requires training data. Its "training" would involve internal development and optimization by the manufacturer using various chemical and biological samples, but this is not detailed in the provided regulatory document.
9. How the Ground Truth for the Training Set Was Established
- Ground Truth for Training Set: Not applicable as there is no described AI/ML training set. The assay's performance relies on the specific antibodies and reagents designed to detect propoxyphene, and its development would involve internal validation by the manufacturer using known standards and clinical samples, confirmed typically by methods like GC/MS.
§ 862.3700 Propoxyphene test system.
(a)
Identification. A propoxyphene test system is a device intended to measure propoxyphene, a pain-relieving drug, in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of propoxyphene use or overdose or in monitoring levels of propoxyphene to ensure appropriate therapy.(b)
Classification. Class II (special controls). A propoxyphene test system is not exempt if it is intended for any use other than employment or insurance testing or is intended for Federal drug testing programs. The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9, provided the test system is intended for employment and insurance testing and includes a statement in the labeling that the device is intended solely for use in employment and insurance testing, and does not include devices intended for Federal drug testing programs (e.g., programs run by the Substance Abuse and Mental Health Services Administration (SAMHSA), the Department of Transportation (DOT), and the U.S. military).