(84 days)
AssureTech Marijuana Tests are immunochromatographic assays for the qualitative determination of 11-Nor-△9-Tetrahydrocannabinol-9-COOH in human urine at cut-off concentration of 50 ng/mL. The tests are available in a Strip format, a Cup format, a Dip Card format and a Turn Key Split Cup format.
The tests provide only preliminary test results. A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. Gas Chromatography/Mass Spectrometry 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. The tests are intended for over-the-counter and for prescription use.
AssureTech Methamphetamine Tests are immunochromatographic assays for the qualitative determination of d-Methamphetamine in human urine at cut-off concentration of 1000 ng/mL. The tests are available in a Strip format, a Cup format, a Dip Card format and a Turn Key Split Cup format.
The tests provide only preliminary test results. A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. Gas Chromatography/Mass Spectrometry 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. The tests are intended for over-the-counter and for prescription use.
AssureTech Phencyclidine Tests are immunochromatographic assays for the qualitative determination of Phencyclidine in human urine at cut-off concentration of 25 ng/mL. The tests are available in a Strip format, a Dip Card format and a Turn Key Split Cup format.
The tests provide only preliminary test results. A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. Gas Chromatography/Mass Spectrometry 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. The tests are intended for over-the-counter and for prescription use.
The AssureTech Methamphetamine Tests, AssureTech Phencyclidine Tests, and AssureTech Marijuana Tests are immunochromatographic assays that use a lateral flow system for the qualitative detection of d-Methamphetamine, Phencyclidine and Marijuana (target analytes) in human urine. The tests are 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.
The provided text describes the analytical and user performance of various AssureTech drug tests (Methamphetamine, Phencyclidine, and Marijuana) across different formats (Strip, Dip Card, Cup, Turn Key Split Cup). The information outlines specific studies conducted to demonstrate the device meets acceptance criteria.
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state quantitative acceptance criteria in percentages (e.g., "must achieve 90% accuracy"). Instead, it presents results for concentrations at or around the cut-off, and above/below it, demonstrating the device's ability to correctly identify positive and negative samples.
Here's a table summarizing the reported device performance for Methamphetamine, Phencyclidine, and Marijuana tests, based on the precision and comparison studies, which effectively serve as a demonstration of meeting implied acceptance criteria for qualitative immunoassay performance.
Implicit Acceptance Criteria: The device should consistently provide correct qualitative results (positive or negative) around and beyond the defined cut-off concentrations, as confirmed by a gold standard (GC/MS). For concentrations significantly below the cut-off, the device should report negative, and for concentrations significantly above, it should report positive. At the cut-off itself, there might be some variability, but a strong trend toward expected results is desired. The lay-user study indicates a high percentage of correct results.
Reported Device Performance (Excerpted and Summarized):
| Test | Analyte | Cut-off (ng/mL) | Performance at -25% Cut-off (GC/MS) | Performance at +25% Cut-off (GC/MS) | Overall Expert Review Performance (Comparison Study) | Lay User Performance (Overall Correctness) |
|---|---|---|---|---|---|---|
| AssureTech Methamphetamine | d-Methamphetamine | 1000 | Precision: 50-/0+ for all formats and lots (all negative as expected). | |||
| Comparison Study: High number of negative reads (e.g., Viewer A Strip: 9 negative samples at or near cutoff). | Precision: 50+/0- for all formats and lots (all positive as expected). | |||||
| Comparison Study: High number of positive reads (e.g., Viewer A Strip: 14 positive samples at or near cutoff). | High agreement with GC/MS. Few discordant results mainly near cutoff, with some negative readings for samples slightly above cutoff, and some positive readings for samples slightly below cutoff. (e.g., Methamphetamine Strip Viewer A: 974 ng/mL (negative) read positive, 1045 ng/mL (positive) read negative.) | Strip: 100% correct across various predefined concentrations, except for a few discordant results in the comparison studies by lab assistants. Dip Card: ~95-100% correct near cutoff for some users. Turn Key Split Cup: ~95-100% correct near cutoff for some users. Quick Cup: ~95-100% correct near cutoff for some users. | ||||
| AssureTech Phencyclidine | Phencyclidine | 25 | Precision: 50-/0+ for all formats and lots (all negative as expected). | |||
| Comparison Study: High number of negative reads (e.g., Viewer A Strip: 9 negative samples at or near cutoff). | Precision: 50+/0- for all formats and lots (all positive as expected). | |||||
| Comparison Study: High number of positive reads (e.g., Viewer A Strip: 14 positive samples at or near cutoff). | High agreement with GC/MS. Few discordant results mainly near cutoff, with some negative readings for samples slightly above cutoff, and some positive readings for samples slightly below cutoff. (e.g., Phencyclidine Strip Viewer A: 22 ng/mL (negative) read positive, 27 ng/mL (positive) read negative.) | Strip: 95-100% correct near cutoff. Dip Card: 95-100% correct near cutoff. Turn Key Split Cup: 90-100% correct near cutoff. Quick Cup: 90-100% correct near cutoff. | ||||
| AssureTech Marijuana | 11-Nor-△9-Tetrahydrocannabinol-9-COOH | 50 | Precision: 50-/0+ for all formats and lots (all negative as expected). | |||
| Comparison Study: High number of negative reads (e.g., Viewer A Strip: 9 negative samples at or near cutoff). | Precision: 50+/0- for all formats and lots (all positive as expected). | |||||
| Comparison Study: High number of positive reads (e.g., Viewer A Strip: 14 positive samples at or near cutoff). | High agreement with GC/MS. Few discordant results mainly near cutoff, with some negative readings for samples slightly above cutoff, and some positive readings for samples slightly below cutoff. (e.g., Marijuana Strip Viewer A: 46 ng/mL (negative) read positive, 52 ng/mL (positive) read negative.) | Strip: 95-100% correct near cutoff. Dip Card: 90-100% correct near cutoff. Turn Key Split Cup: 95-100% correct near cutoff. Quick Cup: 95-100% correct near cutoff. |
2. Sample Sizes and Data Provenance:
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Precision Studies: Samples were prepared at various concentrations around the cut-off (-100%, -75%, -50%, -25%, cut-off, +25%, +50%, +75%, +100%). For each concentration level, 50 tests were performed (2 runs per day for 25 days). This implies 450 tests per lot per device type for each drug (9 concentration levels * 50 tests). With 3 lots per device and 4 device formats for each of the 3 drugs, the total number of precision tests is substantial (e.g., 450 * 3 lots * 4 formats * 3 drugs = 16,200).
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Comparison Studies (Expert Review): For each drug and each device format, 80 unaltered clinical samples were used (40 negative and 40 positive). These were "blind labeled."
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Lay-user Study: 1638 lay persons participated. They were given blind-labeled urine samples from various concentration levels (Negative, +/-75%, +/-50%, +/-25% of the cutoff). The tables show results for 21 samples per concentration level, for each drug and each device type. Considering there are 7 concentration levels listed, and assuming all 4 formats for all 3 drugs were tested, this amounts to a significant number of samples tested by lay users (21 samples/level * 7 levels * 4 formats * 3 drugs = 1,764 total sample tests, which broadly aligns with "1638 lay persons").
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Data Provenance: The document states "Method comparison studies... were performed in-house..." and "Lay-user study was performed at three intended user sites." The country of origin is not explicitly stated for the clinical samples, but the submitting company is based in Hangzhou, China. The studies appear to be prospective as samples were prepared at specific concentrations and tested.
3. Number of Experts and Qualifications:
- Expert Review (Comparison Study): Three laboratory assistants ("Viewer A", "Viewer B", "Viewer C") were used to read the devices. Their specific qualifications (e.g., years of experience) are not provided in this excerpt, only their role as "laboratory assistants."
- Ground Truth Establishment: The ground truth for the test set (clinical urine samples) in the comparison studies was established using Gas Chromatography/Mass Spectrometry (GC/MS), which is stated as the "preferred confirmatory method" and considered a gold standard for drug detection. For precision studies, samples were "prepared by spiking drug in negative samples" and "Each drug concentration was confirmed by GC/MS."
4. Adjudication Method for the Test Set:
- No explicit adjudication method (e.g., 2+1, 3+1 consensus) is described for the "Viewer" results in the comparison studies. The results for each "Viewer" are presented independently. Discordant results are specifically listed, indicating individual discrepancies rather than a pooled or adjudicated outcome from the laboratory assistants.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No MRMC comparative effectiveness study was done in the context of human readers improving with AI vs. without AI assistance. This document describes the performance of a standalone in vitro diagnostic device (immunochromatographic assay) and its comparison to a gold standard (GC/MS), along with a lay-user study. It does not involve AI assistance for human readers.
6. Standalone (Algorithm Only) Performance:
- The devices themselves are qualitative immunochromatographic assays which provide a visual result (line appears or not). Therefore, their performance, as described in the precision and comparison studies, is essentially standalone performance. There isn't an "algorithm" in the typical AI sense; the "algorithm" is the biochemical reaction and visual interpretation of the test strips/cups. The results tabulated for the "Viewers" (laboratory assistants) and "Lay persons" represent human interpretation of these standalone devices.
7. Type of Ground Truth Used:
- The primary ground truth used for validating the device performance is Gas Chromatography/Mass Spectrometry (GC/MS). This is a highly accurate chemical method for confirming the presence and concentration of specific substances in urine samples.
- For the lay-user study, the ground truth was also established by GC/MS of the prepared urine samples.
8. Sample Size for the Training Set:
- This document describes performance validation studies for a medical device (AssureTech drug tests), not an AI algorithm. Therefore, there is no "training set" in the context of machine learning. The device operates based on fixed immunochromatographic principles. The "precision" and "comparison" studies serve as validation of the device's inherent design and manufacturing consistency.
9. How the Ground Truth for the Training Set was Established:
- As there is no AI algorithm training set, this question is not applicable. The device's operational principles are based on biochemical interactions, not learned patterns from a training dataset.
§ 862.3610 Methamphetamine test system.
(a)
Identification. A methamphetamine test system is a device intended to measure methamphetamine, a central nervous system stimulating drug, in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of methamphetamine use or overdose.(b)
Classification. Class II (special controls). A methamphetamine 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).