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David Home Pregnancy Test Cassette is an in-vitro diagnostic test for the qualitative determination of human chorionic gonadotropin (HCG) in the urine to aid in early detection of pregnancy, based on lateral flow immunoassay. It is intended for the Over-the-Counter Use only.

David Professional Pregnancy Test Cassette is an in-vitro diagnostic test for the qualitative determination of human chorionic gonadotropin (HCG) in the urine to aid in early detection of pregnancy, based on lateral flow immunoassay. It is intended for prescription use only.

David Pregnancy Test Cassette will be designed in one format:Cassette.The Cassette kit consists of one test device, a disposable plastic dropper, and a package insert. Each test strip contains mouse monoclonal anti-a-hCG antibody coated membrane and a pad containing mouse monoclonal anti-ß-hCG antibody colloidal gold conjugate. The control antibodies are goat anti-mouse IgG polyclonal antibody.

The provided document describes the performance characteristics and studies for the "David Home Pregnancy Test Cassette" and "David Professional Pregnancy Test Cassette".

Here's an analysis of the acceptance criteria and supporting studies:

1. Table of Acceptance Criteria and Reported Device Performance

| Acceptance Criteria Category | Specific Criteria | Reported Device Performance and Results |
|----------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------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| Sensitivity (Detection Limit) | The positive ratio of samples containing concentrations higher than 25 mIU/mL HCG should be more than 95%. | 100% positive ratio for samples with 25 mIU/mL HCG and above (for both professional and home use, detected by both professional and lay users). At 22.5 mIU/mL HCG, positive ratios were 50% (professional), 56% (home by professional), and 45% (home by lay user). The minimum detection limit is stated as 25 mIU/mL HCG. |
| Specificity (Cross-reactivity) | No cross-reaction with LH, FSH, and TSH at specified high concentrations. | No cross-reaction observed with LH at 500 mIU/mL, FSH at 1000 mIU/mL, and TSH at 1000 μIU/mL for both 0 mIU/mL HCG and 25 mIU/mL HCG spiked samples across 3 lots. |
| Interference | No interference from various exogenous compounds at specified concentrations. | No interference observed from a list of substances (e.g., Glucose, Albumin, Bilirubin, Hemoglobin, Acetaminophen, Aspirin, etc.) at their tested concentrations, in both negative and 25 mIU/mL HCG positive samples. |
| pH Interference | No interference across a specified pH range. | pH ranging from 3 to 10 in urine samples does not interfere with the performance of the test in negative and 25 mIU/mL HCG positive samples. |
| Specific Gravity Interference | No interference across a specified specific gravity range. | Specific gravity ranging from 1.000 to 1.050 in urine samples does not interfere with the performance of the test in negative and positive urine. |
| High Dose Hook Effect | No high dosage hook effect up to a very high HCG concentration. | No hook effect observed up to 2,000,000 mIU/mL hCG. |
| hCG ß-core fragment effects | No interference from high levels of beta core fragment. | No hook effect observed at an hCG ß-core fragment concentration up to 100,000 pmol/L. |
| Precision/Reproducibility | Good repeatability between lots and within lot. For concentrations higher than 25 mIU/mL HCG, all results should be positive. For concentrations below 20 mIU/mL HCG, 98% results should be negative. | For HCG concentrations 25 mIU/mL and above, 100% positive results were obtained across all 3 lots (150/150 for each lot). For HCG concentrations 16 mIU/mL and below, 100% negative results were obtained (150/150 for each lot). At 18.75 mIU/mL, 1/150 positive results were observed across all 3 lots. At 20 mIU/mL, 5/150, 3/150, and 2/150 positive results were observed across lots 1, 2, and 3 respectively, meaning >97% negative results. The study concluded good repeatability. |
| Method Comparison (Professional vs. Predicate) | 100% agreement between the candidate device (Professional) and the predicate device. | Positive, Negative, and Total coincidence rates were all 100% (153 positive, 207 negative, total 360 samples). |
| Method Comparison (Home vs. Predicate) | 100% agreement between the candidate device (Home) and the predicate device. | Positive, Negative, and Total coincidence rates were all 100% (153 positive, 207 negative, total 360 samples). |
| Lay-user Concordance | High concordance between lay-user results and professional results for the Home Pregnancy Test Cassette. Lay users find the test easy to use and understand instructions/labeling. | Positive, Negative, and Total coincidence rates between non-professionals and professionals were all 100% (153 positive, 207 negative, total 360 samples). Lay-user study with spiked samples showed 100% positive for 27.5 mIU/mL HCG and 99% negative for 20 mIU/mL HCG. Questionnaire results indicated lay-users found the test easy to use and understood labeling. Flesch-Kincaid showed readability for 8th-grade education. |

2. Sample Size Used for the Test Set and Data Provenance

• Precision/Reproducibility Study Test Set:

  • Sample Size: For each HCG concentration level (0, 16, 18.75, 20, 25, 27.5, 100 mIU/mL), 150 tests were performed per lot, across 3 lots. Total tests per concentration = 150 * 3 = 450. Total tests in this study = 7 concentrations * 450 tests/concentration = 3150 tests.
  • Data Provenance: Samples were urine spiked with HCG. The study was conducted at three (3) sites. The country of origin is not explicitly stated for the samples themselves but the applicant is from China. It is a prospective study (samples were used in the study, implying prepared for the study).

• Detection Limit Study Test Set:

  • Sample Size: For each HCG concentration level (0, 12.5, 16, 18.75, 20, 22.5, 25, 27.5, 50, 100 mIU/mL), 90 tests were performed at each of the 3 test sites (total 270 tests per concentration). Each 90 tests at a site comprised:
    • Professional Test Kit: 30 tests by professionals
    • Home Use Test Kit (by professionals): 30 tests by professionals
    • Home Use Test Kit (by lay users): 30 tests by lay users
  • Data Provenance: Samples were urine spiked with HCG. The study was conducted at three (3) sites. Prospective nature, similar to the precision study.

• Analytical Specificity (Cross-reactivity) Test Set:

  • Sample Size: 20 fresh urine specimens (10 healthy non-pregnant women, 10 healthy men) were used for each hormone concentration (LH, FSH, TSH) spiked into negative (0 mIU/mL HCG) and positive (25 mIU/ml HCG) samples. This was done for 3 lots.
  • Data Provenance: Urine specimens from healthy non-pregnant women and men. Prospective.

• Interference Study Test Set:

  • Sample Size: Not explicitly stated, but "Negative and positive hCG urine samples (25 mIU/mL) were individually spiked with the substances listed... Three devices of each format were tested."
  • Data Provenance: Urine samples spiked with HCG and interfering substances. Prospective.

• pH Interference Study Test Set:

  • Sample Size: Not explicitly stated, but "Negative and positive hCG urine samples (25 mIU/mL) were tested across a pH range of 3-10."
  • Data Provenance: Urine samples pH adjusted and spiked with or without HCG. Prospective.

• Specific Gravity Interference Study Test Set:

  • Sample Size: Not explicitly stated, but "The device was challenged with negative urine and positive urine with specific gravity from 1.000 to 1.050."
  • Data Provenance: Urine samples with adjusted specific gravity and spiked with or without HCG. Prospective.

• High Dose Hook Effect Study Test Set:

  • Sample Size: Not explicitly stated, but "Negative urine specimens were spiked with high hCG concentration of ranging from 50 mIU/mL to 2000,000 mIU/mL. All samples yielded the expected positive results."
  • Data Provenance: Urine samples spiked with high HCG concentrations. Prospective.

• Effects of hCG ß-core fragment Test Set:

  • Sample Size: Not explicitly stated how many actual urine samples, but "Negative urine hCG (containing 0 mIU/mL hCG,16mIU/mL HCG) and positive urine samples (containing 27.5 mIU/mL hCG) were spiked with hCG beta core fragment standard... Samples of each concentration were tested 10 times with the professional and lay-user respectively." (total 20 tests per concentration per lot, across 3 lots)
  • Data Provenance: Urine samples spiked with HCG and beta-core fragment. Prospective.

• Method Comparison Study Test Set:

  • Sample Size: 360 fresh women urine samples.
  • Data Provenance: "fresh women urine samples". Country of origin not specified, but likely from China given the applicant. This seems to be a prospective collection or at least fresh samples used in a current study.

• Lay-user Study Test Set:

  • Sample Size: 120 female volunteers (40 from each of three sites) for their own urine samples. Additionally, each volunteer tested 3 other double-blind numbered samples spiked with HCG (concentrations not specified but one example given is 27.5mIU/mL and 20mIU/mL HCG). This implies 120 * 3 = 360 spiked tests.
  • Data Provenance: "fresh women urine samples" and urine samples spiked with HCG. Prospective, involving human volunteers.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts

The document does not explicitly state the number or qualifications of "experts" used to establish the ground truth in the traditional sense of medical image interpretation or pathology review.

• For analytical performance studies (Precision, Detection Limit, Specificity, Interference, etc.), the "ground truth" for HCG concentration is established by the known concentrations of spiked HCG in the urine samples, traceable to the WHO International Standard.
• For the Method Comparison Study, the "ground truth" is the result from the predicate device (Wondfo One Step HCG Urine Pregnancy Test, K043443) when tested by professionals. The results from the candidate device (both professional and home use) were compared against this predicate result.
• In the Precision/Reproducibility and Detection Limit studies, "9 operators" and "3 operators" (plus 30 volunteers for detection limit) were involved. Their qualifications are not specified beyond being "operators" or "professionals".
• For the Lay-user study, the ground truth for the volunteers' own samples would be their actual pregnancy status (which would likely be confirmed by clinical methods or laboratory testing, though not specified as such in this document). For the spiked samples, the ground truth is the known spiked HCG concentration.

Therefore, for the analytical studies, the ground truth is based on known sample characteristics. For the method comparison, it's based on a predicate device's performance handled by "professionals". "Experts" with specific qualifications (e.g., radiologists) are not applicable to this type of in-vitro diagnostic device.

4. Adjudication Method for the Test Set

Adjudication methods (like 2+1, 3+1) are typically used in studies where human readers independently interpret images or clinical data, and then discrepancies are resolved. This is not directly applicable to a lateral flow immunoassay pregnancy test, which provides a qualitative "positive" or "negative" result based on visual lines.

• For the Precision/Reproducibility and Detection Limit studies: The results are reported as positive or negative counts across multiple tests. There's no mention of an adjudication process to resolve differing readings on the same test, suggesting direct reading of the test results.
• For the Method Comparison Study: The comparison is directly between the result of the candidate device and the predicate device. If there were discrepancies, the document does not describe a formal adjudication process; instead, it reports a 100% agreement, implying no discrepancies or that any were resolved instantly during the testing by professionals.
• For the Lay-user study: Lay users conducted the test according to instructions. The results from their tests were then compared to reference (likely professional reading of their own samples and known HCG content of spiked samples). No formal "adjudication" in the sense of a third-party expert review of conflicted readings is described.

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

An MRMC comparative effectiveness study is not applicable to this device. This device is an in-vitro diagnostic test for HCG, not an AI-assisted diagnostic imaging device that involves interpretation by human readers. Therefore, there is no AI component or human reader improvement with AI to report effect sizes for.

6. If a Standalone (i.e. algorithm only without human-in-the loop performance) Was Done

This question is not applicable. The device is a lateral flow immunoassay. Its "performance" is determined by the biochemical reaction on the strip and the visual interpretation of lines, which is inherently a "human-in-the-loop" visual interpretation (even for the "home use" version). There is no "algorithm only" component.

7. The Type of Ground Truth Used

• For analytical performance studies (Precision, Detection Limit, Specificity, Interference, Hook Effect, Beta-core fragment): The ground truth was based on known concentrations of HCG or other substances spiked into urine samples, traceable to the WHO International Standard (5th WHO Chorionic Gonadotrophin, NIBSC code: 07/364).
• For the Method Comparison Study: The ground truth was established by the results from a legally marketed predicate device (Wondfo One Step HCG Urine Pregnancy Test) when tested by professionals.
• For the Lay-user study: The ground truth for volunteer's own samples would implicitly be their actual clinical pregnancy status, but this isn't detailed. For the spiked samples used in the lay-user study, the ground truth was the known spiked HCG concentration.

8. The Sample Size for the Training Set

The document describes performance studies for device validation. It does not mention any "training set" in the context of an algorithm or AI model development. This is an IVD device, not a machine learning algorithm.

9. How the Ground Truth for the Training Set Was Established

Not applicable, as there is no "training set" for an algorithm.

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