(67 days)
Wondfo T-Cup® Multi-Drug Urine Test Cup tests are competitive binding, lateral flow immunochromatographic assays for qualitative and simultaneous detection of Amphetamine, Secobarbital, Oxazepam, Cocaine, 2ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine, Methylenedioxymethamphetamine, Morphine, Methadone, Oxycodone, Phencyclidine, Propoxyphene, Nortriptyline and Cannabinoids in human urine at the cutoff concentrations of:
| Drug (Identifier) | Cut-off level |
|---|---|
| Amphetamine (AMP) | 1000 ng/mL or 500 ng/mL |
| Buprenorphine (BUP) | 10 ng/mL |
| Secobarbital (BAR) | 300 ng/mL |
| Oxazepam (BZO) | 300 ng/mL |
| Cocaine (COC) | 300 ng/mL or 150 ng/mL |
| 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) | 300 ng/mL |
| Methamphetamine (MET) | 1000 ng/mL or 500 ng/mL |
| Methylenedioxymethamphetamine (MDMA) | 500 ng/mL |
| Morphine (MOP 300/OPI 2000) | 2000 ng/mL or 300 ng/mL |
| Methadone (MTD) | 300 ng/mL |
| Oxycodone (OXY) | 100 ng/mL |
| Phencyclidine (PCP) | 25 ng/mL |
| Propoxyphene (PPX) | 300 ng/mL |
| Cannabinoids (THC 50) | 50 ng/mL |
Wondfo T-Cup® Multi-Drug Urine Test Cup offers any combinations from 2 to 15 drugs of abuse tests but only one cutoff concentration under same drug condition will be included per device. It is for in vitro diagnostic use only,
The tests may yield positive results for the prescription drugs Buprenorphine, Oxazepam, Secobarbital, Propoxyphene, and Oxycodone when taken at or above prescribed doses. It is not intended to distinguish between prescription use or abuse of these drugs. Clinical consideration and professional judgment should be applied to any drug of abuse test result, particularly in evaluating a preliminary positive result.
The tests provide only preliminary results. To obtain a confirmed analytical result, a more specific alternate chemical method must be used. GC/MS or LC/MS is the recommended confirmatory method.
Wondfo T-Cup® Multi-Drug Urine Test Cup are immunochromatographic assays that use a lateral flow system for the qualitative detection of Amphetamine, Buprenorphine, Secobarbital, Oxazepam, Cocaine, 2ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine,Methamphetamine, Methylenedioxymethamphetamine, Morphine, Methadone, Oxycodone, Phencyclidine, Propoxyphene, Nortriptyline and Cannabinoids in human urine. Each T-Cup® Multi-Drug Urine Test Cup device consists of a test cup and a package insert. Each test cup is sealed with two sachets of desiccant in an aluminum pouch.
This document is a 510(k) Summary for the Wondfo T-Cup® Multi-Drug Urine Test Cup, a rapid diagnostic device for detecting various drugs of abuse in urine. It describes the device's performance characteristics and a "lay-user study" that can be interpreted as a clinical study for a consumer-facing device.
Here's an analysis of the acceptance criteria and study data based on the provided text, framed to address your questions for an AI/ML device where applicable (though this device is an in-vitro diagnostic, not an AI/ML system):
Acceptance Criteria and Device Performance for Wondfo T-Cup® Multi-Drug Urine Test Cup
Since this is an in-vitro diagnostic device and not an AI/ML system, the "acceptance criteria" are typically defined by precision, specificity, linearity (if applicable), stability, and method comparison studies against a gold standard (LC/MS or GC/MS). The study described for the "lay-user" simulates a real-world use case for intended over-the-counter (OTC) use and provides data on how lay users interpret the results around the device's cut-off.
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state "acceptance criteria" in a pass/fail form for the lay-user study. Instead, it presents the results as percentages of correct results at different concentrations relative to the cutoff. For in-vitro diagnostics like this, the implicit acceptance criteria for performance usually revolve around high agreement with confirmed analytical methods (LC/MS or GC/MS), particularly around the cutoff concentrations, and demonstrating usability for the intended user (lay-user in this case).
The performance data for the "lay-user study" is provided for various drugs at different concentrations relative to the cutoff. A "correct result" implies agreement with the LC/MS or GC/MS ground truth.
| Drug (Cut-off) | Concentration | Negative Results | Positive Results | Total Samples | Percentage of Correct Results (%) |
|---|---|---|---|---|---|
| AMP 500 | -100% cutoff | 20 | 0 | 20 | 100% |
| -75% cutoff | 20 | 0 | 20 | 100% | |
| -50% cutoff | 20 | 0 | 20 | 100% | |
| -25% cutoff | 18 | 2 | 20 | 90% | |
| +25% cutoff | 2 | 18 | 20 | 90% | |
| +50% cutoff | 0 | 20 | 20 | 100% | |
| +75% cutoff | 0 | 20 | 20 | 100% | |
| BAR 300 | -100% cutoff | 20 | 0 | 20 | 100% |
| -75% cutoff | 20 | 0 | 20 | 100% | |
| -50% cutoff | 20 | 0 | 20 | 100% | |
| -25% cutoff | 18 | 2 | 20 | 90% | |
| +25% cutoff | 2 | 18 | 20 | 90% | |
| +50% cutoff | 0 | 20 | 20 | 100% | |
| +75% cutoff | 0 | 20 | 20 | 100% | |
| ... (similarly for all drugs/cutoffs listed in the "Lay-User Study Results" tables) |
The percentage of correct results at concentrations -100%, -75%, -50%, +50%, +75% demonstrated 100% accuracy in the lay-user study for most drugs. Performance around the cutoff (at +/- 25% of cutoff) showed some misclassifications, typically around 85-95% accuracy.
2. Sample Size Used for the Test Set and Data Provenance
The primary test set for the device's performance is referred to as "Precision studies," "Comparison Studies," and "Lay-user study."
- Precision Studies: For each drug and each concentration (-100% cutoff, -75% cutoff, -50% cutoff, -25% cutoff, +25% cutoff, +50% cutoff, +75% cutoff, and +100% cutoff), tests were performed two runs per day for 25 days. This means a total of 50 tests per concentration per lot. With 3 lots, this is 150 tests per concentration level per drug. The total number of concentrations varied per drug, but on average there are roughly 8 concentrations, so 1200 individual tests per drug type.
- Comparison Studies (In-House): 80 unaltered urine samples (40 negative and 40 positive) were used. The provenance of this data (e.g., country of origin) is not explicitly stated but implied to be from an internal study ("performed in-house"). The samples were retrospective as they were prepared with spiked drug concentrations and used as "unaltered urine samples."
- Lay-User Study:
- Configuration 1 (AMP 500, MET 500, MOP 300, COC 150): 89 males and 51 females participated, totaling 140 participants.
- Configuration 2 (AMP 1000, MET 1000, MOP 2000 (OPI), COC 300): 84 males and 56 females participated, totaling 140 participants.
- Each participant was given 1 blind labeled sample. For each drug, sample concentrations were -100%, +/-75%, +/-25% of the cutoff. Given there are 7 concentrations listed for each drug in the lay-user study tables, and a total of 20 samples per concentration level, this indicates 140 samples per drug (7 concentrations x 20 samples/concentration).
- Data provenance: "Urine samples were prepared... by spiking drug(s) into drug free-pooled urine specimens." This indicates the samples were synthetic/controlled (spiked), not necessarily from real patients. The study was likely conducted in China, given the manufacturer's location (Guangzhou Wondfo Biotech Co., Ltd.). The study is prospective in the sense that participants were recruited to read the tests.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The ground truth for all studies (Precision, Comparison, and Lay-User) was established using LC/MS or GC/MS (Liquid Chromatography-Mass Spectrometry or Gas Chromatography-Mass Spectrometry). These are highly accurate and widely accepted analytical methods for chemical substance identification and quantification, considered the "gold standard" for drug testing. No human experts are explicitly mentioned as establishing the initial ground truth for the drug concentrations, as this is laboratory methodologically determined.
For the Comparison Studies (In-House), "three operators" ran the samples. Their qualifications are not specified beyond being "operators," but they would be trained lab personnel capable of correctly performing the tests and interpreting the results.
4. Adjudication Method for the Test Set
- Precision Studies: No explicit adjudication method is mentioned for individual readings within daily runs. The overall results are summarized by tallying positive/negative results across all runs and lots.
- Comparison Studies (In-House): "Operators ran 80 (40 negative and 40 positive) unaltered urine samples." The results were then compared to LC/MS or GC/MS. The tables show results for Viewer A, Viewer B, and Viewer C, implying three independent readers/operators performed and reported the results. Discordant results are individually listed for each viewer against the LC/MS result, indicating that each viewer's interpretation was recorded, and there was no internal adjudication between the viewers before comparison to the ground truth.
- Lay-User Study: "Each participant was provided with... 1 blind labeled sample and a device." This suggests no formal adjudication among lay-users. Each participant's reading was taken as their individual result and then compared against the LC/MS or GC/MS ground truth.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, and its effect size
No, a traditional MRMC comparative effectiveness study was not done in the context of human readers improving with AI vs. without AI assistance. This device is an in-vitro diagnostic, not an AI-assisted diagnostic.
However, the "Comparison Studies" with three "Viewers" (human operators) against the LC/MS/GC/MS ground truth, and the "Lay-User Study" where multiple lay participants interpreted the results, do resemble aspects of MRMC studies in that they evaluate multiple readers (operators/lay users) across multiple cases (samples). The "effect size" here would be the agreement of the device, as interpreted by human readers, with the gold standard. The tables show detailed agreement and disagreement for various drugs and concentrations. For example, in the "Comparison Studies" for AMP 500, Viewer A had 2 false positives near cutoff negative and 30 true positives near cutoff positive, compared to LC/MS.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
This question is not applicable as the device is not an algorithm or AI. It is a rapid diagnostic test that produces a visual result that must be interpreted by a human user. Its performance is inherently tied to human interpretation.
7. The Type of Ground Truth Used
The type of ground truth used for all performance evaluations (precision studies, in-house comparison studies, and lay-user studies) was confirmed analytical results from LC/MS or GC/MS (Liquid Chromatography-Mass Spectrometry or Gas Chromatography-Mass Spectrometry). This is a highly objective and quantitative chemical analysis, serving as the definitive measurement of drug concentration in the urine samples.
8. The Sample Size for the Training Set
This question is not applicable. This is an in-vitro diagnostic device (a chemical test) and does not involve AI/ML requiring a training set in the conventional sense. The "training" of the device is through its chemical formulation and manufacturing process, optimized through R&D, rather than data-driven machine learning.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no "training set" in the context of AI/ML for this device. The development of the test's performance characteristics (e.g., sensitivity, specificity, cutoff levels) would have been established during the research and development phase of the immunochromatographic assay, typically through extensive chemical and biological experimentation to optimize reagent concentrations and reaction conditions.
§ 862.3100 Amphetamine test system.
(a)
Identification. An amphetamine test system is a device intended to measure amphetamine, a central nervous system stimulating drug, in plasma and urine. Measurements obtained by this device are used in the diagnosis and treatment of amphetamine use or overdose and in monitoring levels of amphetamine to ensure appropriate therapy.(b)
Classification. Class II (special controls). An amphetamine 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).