(62 days)
The ACON AMP One Step Amphetamine Test Strip and ACON AMP One Step Amphetamine Test Device are rapid chromatographic immunoassays for the qualitative detection of amphetamine in human urine at a cut-off concentration of 1,000 ng/mL. These tests are for professional and point of care use.
The ACON AMP One Step Amphetamine Test Strip and ACON AMP One Step Amphetamine Test Device are competitive binding, lateral flow immunochromatographic assays for the qualitative screening of amphetamine, in a urine sample. The test is based on the principle of antigen-antibody immunochemistry. It utilizes a monoclonal antibody to selectively detect elevated levels of amphetamine in urine at a cut-off concentration of 1,000 ng/mL. These tests can be performed without the use of an instrument.
A drug-positive urine specimen will not generate a colored line in the test line region. while a drug negative urine specimen will generate a line in the test line region. To serve as a procedural control, a colored line will always appear at the control line region if the test has been performed properly.
Acceptance Criteria and Device Performance Study for ACON® AMP One Step Amphetamine Test
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for the ACON® AMP One Step Amphetamine Test Strip and Test Device are implicitly defined by the reported performance metrics. While explicit target percentages are not stated, the study aims to demonstrate substantial equivalence to a predicate device and established analytical techniques. The reported performance is as follows:
| Performance Metric | Acceptance Criteria (Implicit) | ACON® AMP One Step Amphetamine Test Strip (vs. GC/MS) | ACON® AMP One Step Amphetamine Test Device (vs. GC/MS) |
|---|---|---|---|
| Accuracy (Overall Agreement) | High agreement | 96% (93-98% CI) | 95% (92-97% CI) |
| Positive Agreement | High positive agreement | 97% (93-99% CI) | 96% (92-99% CI) |
| Negative Agreement | High negative agreement | 95% (90-93% CI) * | 95% (90-97% CI) * |
| Positive Predictive Value (PPV) | High PPV | 94% (88-97% CI) | 94% (88-97% CI) |
| Negative Predictive Value (NPV) | High NPV | 97% (94-99% CI) | 97% (93-99% CI) |
| Sensitivity (at cut-off 1000 ng/mL) | Ability to detect at cut-off | 12/30 (40%) detected as negative, 18/30 (60%) as positive | 9/30 (30%) detected as negative, 21/30 (70%) as positive |
| Sensitivity (at 125% cut-off) | High sensitivity | 28/30 (93%) positive | 29/30 (97%) positive |
| Sensitivity (at 150% cut-off) | High sensitivity | 30/30 (100%) positive | 30/30 (100%) positive |
| Sensitivity (at 200% cut-off) | High sensitivity | 30/30 (100%) positive | 30/30 (100%) positive |
| Specificity (Cross-Reactivity) | Detect amphetamine selectively | D-Amphetamine: 100%, L-Amphetamine: 2%, D,L-Amphetamine: 33%, MDA: 50%, Phentermine: 33% | (Same as Strip) |
| Interfering Substances | No interference from common substances | No interference observed with listed substances at 100 ug/mL | (Same as Strip) |
| Intra and Inter-assay Variability | High precision | Demonstrated high level of precision (within run, between run, and between days) | Demonstrated high level of precision (within run, between run, and between days) |
*Note: The negative agreement for the Strip vs GC/MS in the document is reported as 95% (90-93%), which seems inconsistent with the 95% value. The CI suggests the actual negative agreement might be within the lower bound of 90-93%. For the purpose of reporting, I've kept the stated 95%.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: 300 clinical specimens were used for the accuracy study.
- For sensitivity testing, 30 specimens were tested at each of 7 concentration levels (negative urine, 500, 750, 1,000, 1,250, 1,500, and 2,000 ng/mL), totaling 210 tests for each device type in this specific aspect.
- Data Provenance: The document does not specify the country of origin for the clinical specimens. The data is reported as a "clinical evaluation," implying that these were collected from actual patients. It is a retrospective study as the samples were collected prior to testing with the ACON devices and compared against a reference method (GC/MS) later.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts
This type of diagnostic device (immunochromatographic test for drug detection) typically relies on laboratory analytical methods for ground truth, not human expert consensus for image interpretation.
- Ground Truth Method: The primary ground truth for the accuracy study was established using Gas Chromatography/Mass Spectrometry (GC/MS), which is considered a gold standard for drug detection and quantification in urine.
- Experts: The document does not mention the use of human experts (e.g., radiologists) to interpret results for establishing ground truth. The GC/MS analysis would have been performed by qualified laboratory personnel, but these are not "experts" in the sense of clinical interpretation as might be for imaging studies.
4. Adjudication Method for the Test Set
Not applicable. The ground truth was established by comparison to a recognized analytical gold standard (GC/MS) and a predicate device, not by expert adjudication of clinical outcomes or interpretations. Device results were compared directly to the GC/MS results.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
Not applicable. This device is a rapid chromatographic immunoassay without a human-in-the-loop interpretative component that would typically involve multiple readers assessing cases. The test provides a visual, qualitative end result (presence or absence of a line) that is read directly.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
Yes, the studies presented are essentially standalone performance evaluations of the ACON AMP One Step Amphetamine Test Strip and Test Device. The devices themselves produce the analytical result (visual lines), and this result is then compared to a reference method (GC/MS) to determine their accuracy. There is no "human-in-the-loop" assistance for interpreting the device's output – the output is the final answer.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
The primary ground truth used for the accuracy and specificity studies was Gas Chromatography/Mass Spectrometry (GC/MS) analysis, which is an analytical gold standard for quantitative drug detection. Additionally, the LifeSign Status DS™ AMP One-Step Amphetamine Test (a predicate device) served as a comparative reference for some aspects of the accuracy study.
8. The Sample Size for the Training Set
The provided information pertains to the performance evaluation of the manufactured devices, not to an algorithm that requires a training set. Immunochromatographic assays like this are developed using chemical and biological principles and do not undergo machine learning training in the same way as AI algorithms. Therefore, there is no "training set" in this context.
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 device's "knowledge" or functionality is inherent in its biochemical design and manufacturing process, not learned from data.
§ 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).