(59 days)
Wondfo Amphetamine Urine Test AMP 500 Cup is an immunochromatographic assay for the qualitative determination of Amphetamine in human urine at a Cut-Off concentration of 500 ng/mL. This test is calibrated to d-Amphetamine (calibrator).
The test provides only preliminary test results. A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. GC/MS is the preferred confirmatory method. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary result is positive. For in vitro diagnostic use only. This test is intended for over-the-counter (OTC) consumer use as the first step in a twostep process to provide consumers with information concerning the presence of the above stated drugs or their metabolites in a urine sample. Information regarding confirmatory testing- the second step in the process, is provided in the package labeling.
Wondfo Amphetamine Urine Test AMP 500 DipCard is an immunochromatographic assay for the qualitative determination of Amphetamine in human urine at a Cut-Off concentration of 500 ng/mL. This test is calibrated to d-Amphetamine (calibrator).
The test provides only preliminary test results. A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. GC/MS is the preferred confirmatory method. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary result is positive. For in vitro diagnostic use only. This test is intended for over-the-counter (OTC) consumer use as the first step in a twostep process to provide consumers with information concerning the presence or absence of the above stated drugs or their metabolites in a urine sample. Information regarding confirmatory testing- the second step in the process, is provided in the package labeling.
Wondfo Cocaine Urine Test COC 150 Cup is an immunochromatographic assay for the qualitative determination of Benzoylecgonine in human urine at a Cut-Off concentration of 150 ng/mL. This test is callbrated to Benzoylecgonine (calibrator).
The test provides only preliminary test results. A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. GC/MS is the preferred confirmatory method. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary result is positive. For in vitro diagnostic use only. This test is intended for over-the-counter (OTC) consumer use as the first step in a twostep process to provide consumers with information concerning the presence or absence of the above stated drugs or their metabolites in a urine sample. Information regarding confirmatory testing- the second step in the process, is provided in the package labeling.
Wondfo Cocaine Urine Test COC 150 DipCard is an immunochromatographic assay for the qualitative determination of Benzoylecgonine in human urine at a Cut-Off concentration of 150 ng/mL. This test is callbrated to Benzoylecgonine (calibrator).
The test provides only preliminary test results. A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. GC/MS is the preferred confirmatory method. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary result is positive. For in vitro diagnostic use only. This test is intended for over-the-counter (OTC) consumer use as the first step in a twostep process to provide consumers with information concerning the presence of the above stated drugs or their metabolites in a urine sample. Information regarding confirmatory testing- the second step in the process, is provided in the package labeling.
Wondfo Methamphetamine Urine Test MET 500 Cup is an immunochromatographic assay for the qualitative determination of Methamphetamine in human urine at a Cut-Off concentration of 500 ng/mL. This test is calibrated to d-Methamphetamine (calibrator).
The test provides only preliminary test results. A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. GC/MS is the preferred confirmatory method. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary result is positive. For in vitro diagnostic use only. This test is intended for over-the-counter (OTC) consumer use as the first step in a twostep process to provide consumers with information concerning the presence or absence of the above stated drugs or their metabolites in a urine sample. Information regarding confirmatory testing- the second step in the process, is provided in the package labeling.
Wondfo Amphetamine Urine Test MET 500 DipCard is an immunochromatographic assay for the qualitative determination of Methamphetamine in human urine at a Cut-Off concentration of 500 ng/mL. This test is calibrated to d-Methamphetamine (calibrator).
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. Clinical consideration and professional judgment should be exercised with any drug of abuse test result, particularly when the preliminary result is positive. For in vitro diagnostic use only. This test is intended for over-the-counter (OTC) consumer use as the first step in a twostep process to provide consumers with information concerning the presence or absence of the above stated drugs or their metabolites in a urine sample. Information regarding confirmatory testing- the second step in the process, is provided in the package labeling.
WONDFO Urine Test devices are immunochromatographic assays for cocaine, amphetamine and Methamphetamine. Each assay test is a lateral flow, one step system for the qualitative detection of Benzoylecgonine, or D-amphetamine or D-methamphetamine (target analyte) in human urine. The product is a single-use in vitro diagnostic device, which comes in the form of: DipCards, or Cups. It contains a Test Device (in one of the two formats), a package insert and a urine cup. Each test device is sealed with a desiccant in an aluminum pouch.
The document provides information on the acceptance criteria and performance of the Wondfo Amphetamine/Cocaine/Methamphetamine Urine Tests.
Here's the breakdown:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state "acceptance criteria" in a table format with a direct comparison to performance against those criteria. Instead, it presents performance characteristics (precision, cut-off verification, interference, specificity, effects of specific gravity and pH, agreement with GC/MS, and lay-user performance) which implicitly define the device's acceptable performance. The performance demonstrated is the acceptance criteria met.
Implicit Acceptance Criteria and Reported Device Performance (Summary derived from the text):
| Performance Characteristic | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Precision | Consistent results across concentrations and lots. | Amphetamine (AMP) Dip Card & Cup: For all three lots and both formats: |
| -100%, -75%, -50%, -25% Cut-off: 50-/0+ (Negative) observed for all tests. | ||
| +25%, +50%, +75%, +100% Cut-off: 50+/0- (Positive) observed for all tests. | ||
| At Cut-off: 43+/7- or 44+/6- (Mix of Positive/Negative) observed, indicating expected behavior around the cut-off. | ||
| Cocaine (COC) Dip Card & Cup: Similar results to AMP for all three lots and both formats, demonstrating expected performance across the concentration range and at the cut-off. | ||
| (Methamphetamine (MET) precision data reported in K122961, not detailed here.) | ||
| Cut-off Verification | Accurate classification at and around defined cut-off levels. | All samples at and above +50% cut-off were positive. All samples at and below -50% cut-off were negative for Amphetamine, Cocaine, and Methamphetamine. |
| Interference | No interference from common physiological/pathological substances. | Numerous common substances (listed in the document, pages 10-12) showed no interference at 100 µg/mL. Targeted drugs at 25% above cut-off levels were correctly detected in the presence of these substances. |
| Specificity | Proper reactivity to target analytes and appropriate cross-reactivity. | AMP: D-Amphetamine: 100% reactivity at 500 ng/mL. Cross-reactivity observed with L-Amphetamine (2%), D,L-Amphetamine (33%), Phentermine (33%), Hydroxyamphetamine (6%), MDA (20%). No reaction with D/L-Methamphetamine, Ephedrine, MDE, MDMA at 100,000 ng/mL. |
| COC: Benzoylecgonine: 100% reactivity at 150 ng/mL. Cross-reactivity with Cocaine HCl (40%), Cocaethylene (2.4%), Ecgonine (0.9%), Norcocaine (0.3%). | ||
| MET: D-Methamphetamine: 100% reactivity at 500 ng/mL. 100% reactivity with MDEA, MDA, D/L-Methamphetamine. Cross-reactivity with L-Methamphetamine (5%), L-Amphetamine (1.3%). | ||
| Urine Specific Gravity & pH Effects | Consistent results across a range of urine specific gravity and pH. | Urine samples with specific gravity 1.000-1.035 and pH 4-9 spiked at +/- 25% cut-off levels showed all positive results for samples at and above +25% cut-off and all negative results for samples at and below -25% cut-off. No differences were observed across formats. |
| Agreement with GC/MS (Method Comparison) | High agreement with GC/MS for both negative and positive samples. | AMP (Dip Card & Cup): Across 3 viewers, 0 false positives for negative and low negative samples. For near cut-off negative, 1-2 false positives were reported by viewers. For near cut-off positive and high positive samples, viewers consistently reported positive results with minimal discordance (e.g., 2 samples with GC/MS at 480 or 481 ng/mL were called positive by some viewers, demonstrating sensitivity close to cut-off). COC (Dip Card & Cup): Similar to AMP, with 0 false positives for negative and low negative. Few false positives for near cut-off negative (1-2). High agreement for near cut-off positive and high positive. Discordant results mainly around the cut-off (e.g., GC/MS 145 or 146 ng/mL called positive by viewers).(Methamphetamine (MET) data reported in K122961, not detailed here.) |
| Lay-User Performance | High percentage of correct results by untrained users. | AMP (Cup & Dip Card): 100% correct for -100%, -75%, -50%, +50%, +75% cut-off concentrations. 90-95% correct for -25% and +25% cut-off concentrations (expected variability around cut-off). |
| COC (Cup & Dip Card): 100% correct for -100%, -75%, -50%, +50%, +75% cut-off concentrations. 90% correct for -25% and +25% cut-off concentrations. | ||
| MET (Cup & Dip Card): 100% correct for -100%, -75%, -50%, +50%, +75% cut-off concentrations. 90% correct for -25% and +25% cut-off concentrations. | ||
| All lay users found instructions easy to follow, with a Flesch-Kincaid Grade Level of 7. |
The study demonstrates that the Wondfo Urine Test devices perform as expected for qualitative drug detection around specified cut-off levels, show appropriate specificity, are not significantly affected by common interfering substances or urine properties, and can be used accurately by lay-users. This collective performance data indicates that the devices meet the implied acceptance criteria for their intended use as preliminary, over-the-counter drug screening tests.
Study Details:
2. Sample Size and Data Provenance
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Test Set Sample Size:
- Precision Studies: For each drug concentration, three lots of devices were tested, with two runs per day for 25 days. The number of individual tests per concentration point for each lot is not explicitly stated as a single total, but 50 measurements (e.g., 50-/0+ or 50+/0-) are reported for each concentration for each lot. This implies 50 tests per concentration per lot for each of "Lot 1, Lot 2, Lot 3". Given 9 concentration points per drug, that's 9 * 50 = 450 tests per lot, and 3 lots means 1350 tests per drug for each device format (Cup/DipCard).
- Cut-off Verification: 150 samples were used in total, equally distributed across 5 concentrations (-50%, -25%, cut-off, +25%, +50%). Tested using three different lots of each device by three different operators. (This means 150 samples * 3 lots * 3 operators = 1350 individual test results reported for this section across all drugs and device formats).
- Interference & Specificity Studies: Not explicitly stated as a total N, but substances were added to drug-free urine and target-drug urine (25% above cut-off) and tested using "three batches of each device for all formats."
- Method Comparison (Agreement with GC/MS): 80 unaltered clinical samples (40 negative, 40 positive) were used for each drug (Amphetamine, Cocaine, Methamphetamine) for each device format (Cup/DipCard).
- Lay-user Study: 280 lay persons for Amphetamine devices, 280 for Cocaine devices, and 280 for Methamphetamine devices. Each lay person tested one blind-labeled sample. For each drug, 7 distinct concentration levels with 20 samples per level were used. This means 7 * 20 = 140 samples were prepared for each drug per device format (e.g., AMP Cup), and these samples were then distributed to the 280 lay users (presumably 140 for the Cup and 140 for the DipCard, but this is not explicitly stated for all, though AMP and COC show 140 samples in total distributed across the 7 concentrations for both Cup and DipCard results tables).
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Data Provenance:
- Country of Origin: Wondfo Biotech Co., Ltd. is located in Guangzhou, P.R. China (page 4). The studies were likely conducted internally or by associated labs.
- Retrospective or Prospective: Not explicitly stated, but the "clinical samples" for the method comparison were "unaltered," which often implies prospectively collected real-world samples. The precision and cut-off studies involved "spiking drug in negative samples" which are laboratory-prepared. The lay-user study used prepared samples and was a controlled prospective study.
3. Number of Experts and Qualifications for Ground Truth
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Method Comparison (Agreement with GC/MS):
- The ground truth was established by GC/MS (Gas Chromatography/Mass Spectrometry), which is the preferred confirmatory method for drug testing, considered the "gold standard."
- No human "experts" were listed as establishing ground truth for the test set; the GC/MS analytical results served as the objective gold standard.
- Three "laboratory assistants" were involved in running the Wondfo devices, not in establishing the ground truth. Their qualifications are not provided.
-
Precision, Cut-off, Interference, Specificity, Specific Gravity/pH: The ground truth for these studies was established by the precise preparation of samples with known drug concentrations (confirmed by GC/MS where relevant) and the analytical methods used to prepare and characterize the samples.
-
Lay-user Study: The ground truth for the lay-user study was established by GC/MS for the prepared urine samples.
4. Adjudication Method for the Test Set
- Method Comparison: No formal "adjudication method" among human readers is described for the test sets. The Wondfo device results (read by the laboratory assistants/viewers) were directly compared to the GC/MS ground truth. Discordant results are noted individually for each viewer against the GC/MS result.
- Precision/Cut-off: Not applicable, as results were based on predefined expectations for concentrations.
- Lay-user Study: Not applicable, as each lay person read their assigned sample independently against the GC/MS-confirmed concentration.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No MRMC comparative effectiveness study was explicitly performed or reported in this document to assess how much human readers improve with AI (or rather, with the device) versus without assistance.
- The studies were designed to evaluate the performance of the device itself and the ability of lay users to correctly interpret device results compared to a gold standard (GC/MS).
- The "Method Comparison" section involved three "viewers" (laboratory assistants) independently reading the device results and comparing them to GC/MS. This is a multi-reader study, but it's evaluating the device's accuracy when read by trained personnel, not necessarily the improvement of those readers.
- The "Lay-user study" is also a multi-reader study (280 lay persons), but it's assessing the device's ease of use and accuracy in untrained hands, not an improvement over unassisted human performance.
6. Standalone Performance Study
- Yes, a standalone performance study was done. The core of the document describes the standalone performance of the Wondfo Urine Test device itself.
- The "Precision," "Cut-off," "Interference," and "Specificity" sections evaluate the analytical performance of the device in a laboratory setting when operated by laboratory personnel, without explicit human-in-the-loop decision-making beyond visual interpretation of a test line.
- The "Method Comparison" study explicitly compares the device's qualitative results (interpreted visually by laboratory assistants) against the GC/MS gold standard. This is a direct measure of the device's standalone performance in a simulated clinical context.
7. Type of Ground Truth Used
- The primary ground truth used for all performance studies (precision, cut-off, interference, specificity, method comparison, lay-user study) for drug concentrations was GC/MS (Gas Chromatography/Mass Spectrometry). GC/MS is a highly accurate analytical chemistry technique considered the definitive "confirmatory method" for drug identification and quantification in urine.
- For the lay-user study, the ground truth for ease of use was collected via user surveys.
8. Sample Size for the Training Set
- Not Applicable. This device is an immunochromatographic assay (lateral flow immunoassay), not a machine learning or AI-based device that typically requires a "training set" in the computational sense. The device's performance is based on its chemical and biological design, not a trained algorithm.
9. How the Ground Truth for the Training Set Was Established
- Not Applicable, as there is no "training set" for this type of device. The ground truth for the validation/test samples was established via GC/MS.
§ 862.3250 Cocaine and cocaine metabolite test system.
(a)
Identification. A cocaine and cocaine metabolite test system is a device intended to measure cocaine and a cocaine metabolite (benzoylecgonine) in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of cocaine use or overdose.(b)
Classification. Class II (special controls). A cocaine and cocaine metabolite 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).