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The Psychemedics Microplate EIA for Opiates is an enzyme immunoassay (EIA) for the preliminary qualitative detection of opiates in human head and body hair using a morphine calibrator at 2 ng /10 mg hair cutoff for the purpose of identifying opiate use. This is an in vitro diagnostic device intended exclusively for Psychemedics use only and is not intended for sale to anyone.

The Psychemedics Microplate EIA opiate assay provides only a preliminary analytical test result. A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. Gas or Liquid Chromatography/Mass Spectrometry (GC/MS or LC/MS/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.

The test consists of two parts; a pre-analytical hair treatment procedure (to convert the solid matrix of hair to a measurable liquid matrix) and the screening assay, the Psychemedics Microplate EIA for Opiates. The drug is recovered from the hair using a patented method (U.S. Patent #8,084.215).The screening portion of the test system consists of (1) microplate wells coated with multiple drugs including morphine conjugated to bovine serum albumin (BSA) (patent pending), polyclonal sheep anti-morphine, rabbit anti-goat secondary antibody conjugated to HRP (horseradish peroxidase), substrate [3, 3', 5, 5' tetramethylbenzidine (TMB)}, HCl to acidify the final reaction, and wash buffer for washing the plates. Absorbance in the wells is read with a microplate reader.

The provided text describes the performance testing of the Psychemedics Microplate EIA for Opiates in Hair. However, it does not explicitly state "acceptance criteria" as a separate, pre-defined set of metrics. Instead, the study aims to demonstrate substantial equivalence to a predicate device (Psychemedics RIA Assay for Opiates) and correlation with a confirmatory method (LC/MS/MS).

The "acceptance criteria" can be inferred from the reported performance results, particularly the low discordance with the predicate device and the high agreement with LC/MS/MS, especially for confirmed positive and negative samples.

Here's an analysis of the requested information based on the provided text:

Acceptance Criteria and Reported Device Performance

Inferred Acceptance Criteria:

1. Low discordance with predicate device (RIA Assay for Opiates): The device should show strong agreement with the established predicate method.
2. High agreement with LC/MS/MS confirmation: For definitive positive and negative cases, the EIA result should align with the LC/MS/MS results.
3. Robustness to cosmetic treatments: Cosmetic treatments should not significantly alter the test results for both negative and positive samples.
4. Effective contamination control: The wash procedure should effectively remove external contamination, preventing false positives.
5. Limited cross-reactivity and no interference: The assay should be specific to opiates and not significantly affected by common interfering substances.

Reported Device Performance:

Study Details:

1. Sample sizes used for the test set and the data provenance:

   • Agreement Testing: 383 head hair samples and 90 body hair samples (total 473 hair samples).
   • LC/MS/MS Confirmation: 253 of the above samples were confirmed by LC/MS/MS.
   • Cosmetic Treatments (Negative): 20 opiate-negative hair samples per treatment type (bleach, permanent wave, dye, relaxer, shampoo) for a total of 100 samples.
   • Cosmetic Treatments (Positive): 12 opiate-positive hair samples per treatment type (bleach, permanent wave, dye, relaxer, shampoo) for a total of 60 samples.
   • Contamination Study: 8 hair samples soaked in morphine/water, 8 hair samples soaked in morphine/saline.
   • Data Provenance: Not explicitly stated, but typically these samples would be collected in a controlled or clinical environment for regulatory submissions. Given the context of a US submission, it's highly likely to be originating from the US. The type seems to be retrospective as they are described as "samples" rather than "patients undergoing a diagnostic pathway".

2. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

   • The ground truth for the test set was primarily established by LC/MS/MS (Liquid Chromatography/Mass Spectrometry/Mass Spectrometry), which is described as the "preferred confirmatory method." LC/MS/MS results are considered the gold standard for drug detection in hair, not expert consensus. Therefore, no human experts were explicitly used for establishing the primary ground truth.

3. Adjudication method for the test set:

   • Not applicable in the traditional sense, as the ground truth was established by LC/MS/MS, a quantitative analytical method, not human interpretation requiring adjudication. For discrepancies between the EIA and RIA, the LC/MS/MS method was used as the arbiter: "The samples were negative by LC/MS/MS, demonstrating that the EIA negative results, although discordant with the predicate, are correct."

4. 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:

   • No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This device is an in vitro diagnostic assay, not an AI-assisted diagnostic tool that involves human readers interpreting images or data for improvement. The study focuses on the analytical performance of the assay itself.

5. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:

   • Yes, this study represents a standalone performance evaluation of the Psychemedics Microplate EIA for Opiates. The "algorithm" here refers to the EIA assay's chemical and optical detection mechanism. The performance is assessed purely on its analytical results against a gold standard (LC/MS/MS) and a predicate device (RIA), without human interpretation influencing the primary outcome or a human-in-the-loop component for improved performance. The device provides "preliminary analytical test results," which are then confirmed by other chemical methods.

6. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

   • The primary ground truth used was LC/MS/MS (Liquid Chromatography/Mass Spectrometry/Mass Spectrometry), which is a highly sensitive and specific chemical method considered the "gold standard" for confirming the presence and concentration of drugs in biological samples like hair.

7. The sample size for the training set:

   • The document does not provide information about a separate training set. The data presented appears to be from a validation or test set to demonstrate the device's performance. For in vitro diagnostic assays, the "training" (development and optimization) phase often involves internal experiments and is generally not documented in the same way as a machine learning model's training set in regulatory submissions.

8. How the ground truth for the training set was established:

   • As no training set is explicitly mentioned or described, this information is not available in the provided text.

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