(159 days)
Preview® Digital Pregnancy Test is intended for the qualitative detection of human chorionic gonadotropin (hCG) in urine, as an aid in early detection of pregnancy.
Preview® Digital Pregnancy Test is designed to be tested in dip and midstream modes. Preview® Digital Pregnancy Test consists of a single test strip encased in plastic device housing, with an absorbent tip. The device is in a ready-to-use format and no longer requires assembly before use.
Here's a breakdown of the acceptance criteria and the study details for the Preview Digital Pregnancy Test, based on the provided text:
Acceptance Criteria and Device Performance
The acceptance criteria for qualitative pregnancy tests typically revolve around their sensitivity and specificity (accuracy in detecting or ruling out pregnancy). While explicit "acceptance criteria" are not listed as a separate section with numerical targets, the document demonstrates the device's performance against expected standards for sensitivity (25 mIU/mL) and specificity (100%).
| Acceptance Criteria (Implied/Demonstrated Standard) | Reported Device Performance (Preview Digital Pregnancy Test) |
|---|---|
| Analytical Sensitivity: 100% detection at 25 mIU/mL hCG | 100% detection at 25 mIU/mL hCG (across 3 lots for both dip and in-stream methods) |
| Analytical Specificity: 0% false positives in non-pregnant individuals | 100% specificity (0% false positive rate) in 300 non-pregnant urine samples |
| Hook Effect: No false negatives at high hCG concentrations | No hook effect observed up to 500,000 mIU/mL hCG |
| Interference: No interference from common substances, pH, or specific gravity | No interference observed from 30 listed substances, pH 4-9, and specific gravity 1.000-1.035 |
| Precision: Consistent results across lots, operators, and days at various hCG concentrations | Consistent results demonstrated across 3 lots, 3 lab technicians, and 5 days for various hCG levels and negative samples. |
| Clinical Performance (Positive Conformity): High agreement with predicate device for positive samples | 100% positive conformity with predicate device (both dip and in-stream) |
| Clinical Performance (Negative Conformity): High agreement with predicate device for negative samples | 100% negative conformity with predicate device (both dip and in-stream) |
| Lay User Performance (Positive Conformity): High agreement with professional results for positive samples | 100% positive conformity with professional results (first lay study) |
| Lay User Performance (Negative Conformity): High agreement with professional results for negative samples | 100% negative conformity with professional results (first lay study) |
| Lay User Performance (Correct Results): High percentage of correct results for spiked samples at specified concentrations | 100% correct results for 5 mIU/mL and 25 mIU/mL spiked samples (second lay study) |
Study Information
2. Sample sizes used for the test set and the data provenance:
- Analytical Sensitivity:
- 30 samples per hCG concentration level (0, 5, 12.5, 15, 18.75, 25, 50, 100 mIU/mL) for each of 3 lots (total 30 x 8 x 3 = 720 tests for dip and 720 tests for in-stream).
- Provenance: Samples were prepared "in negative urine pool" and "calibrated against the WHO 4th IS for hCG", suggesting laboratory-prepared (synthetic/spiked) samples.
- Analytical Specificity:
- 300 urine samples (100 each from pre-menopausal, peri-menopausal, and post-menopausal non-pregnant females).
- Provenance: Retrospective, collected from normal, non-pregnant females. Country of origin not specified, but the submitter is from China.
- Hook Effect:
- Samples spiked with hCG concentrations from 6,250 to 500,000 mIU/mL. Specific number of samples per concentration not given, but it implies a range of samples tested across these concentrations.
- Provenance: Laboratory-prepared (spiked) negative urine samples.
- Interfering Substance:
- Urine samples containing 0, 5, 25, and 100 mIU/mL hCG spiked with each interfering substance. Specific number of samples per substance not given.
- Provenance: Laboratory-prepared (spiked) urine samples.
- Precision:
- 50 replicates per hCG concentration (0, 5, 12.5, 15, 18.75, 25, 50, 100, 1000 mIU/mL) for each of 3 lots (total 50 x 9 x 3 = 1350 tests for dip and 1350 tests for in-stream).
- Provenance: Laboratory-prepared (spiked) negative human urine samples.
- Method Comparison Study:
- 300 urine samples collected from women presenting to test for pregnancy (approximately half suspected pregnant).
- Provenance: Prospective collection from unknown locations (likely the submitter's country or chosen clinical sites).
- Lay Person Study (First):
- 200 women for self-testing.
- Provenance: Prospective, collected from women. "Varying educational and occupational backgrounds from three sites were chosen". Country of origin not specified.
- Lay Person Study (Second):
- 200 women for self-testing using spiked samples (100 subjects for 5 mIU/mL hCG and 100 for 25 mIU/mL hCG).
- Provenance: Laboratory-prepared (spiked) negative urine sample pools. "Each testing site had a study administrator to observe or monitor the studies". Country of origin not specified.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Analytical Sensitivity, Specificity, Hook Effect, Interfering Substances, Precision: The ground truth was established by the known concentrations of hCG in the reference standards or spiked samples, traceable to the WHO 4th IS for hCG. This does not involve human experts for ground truth establishment.
- Method Comparison Study: The ground truth for the 300 clinical samples was established by the results of the "predicate device". There's no mention of independent expert adjudication for these samples.
- Lay Person Study (First): The ground truth was established by "professional testing" of the samples. The number and qualifications of these professionals are not specified.
- Lay Person Study (Second): The ground truth was established by the known spiked concentration of hCG (0, 5 mIU/mL, 25 mIU/mL).
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- None specified for any part of the study in terms of expert adjudication.
- For the analytical studies, ground truth was by reference standard/known concentration.
- For the method comparison, the predicate device served as the reference.
- For the first lay person study, "professional testing" served as reference, but the method for their consensus or adjudication is not detailed.
- For the second lay person study, ground truth was by known spike concentration.
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:
- No MRMC study was performed. This device is a standalone digital pregnancy test, not an AI-assisted interpretation system for human readers. Its output is a direct digital result (effectively an "AI" in the sense of an automated algorithm, but without a human-in-the-loop component for interpretation that would be improved by AI assistance).
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, this was a standalone performance study. The device itself provides a digital readout (LCD screen) after interpreting the immunochromatographic assay. The "algorithm" is inherent in the device's mechanism to detect and display the presence or absence of hCG, replacing visual interpretation of lines by a human. The lay person study confirms its standalone performance with non-expert users.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- Known Reference Standards/Spiked Samples: For analytical sensitivity, Hook effect, interfering substances, and precision studies. These are traceable to the WHO 4th International Standard for hCG.
- Predicate Device Results: For the method comparison study.
- Professional Testing Results: For the first lay person study. (Specifics not provided for how "professional testing" itself established ground truth).
- Known Spiked Sample Concentrations: For the second lay person study.
8. The sample size for the training set:
- Not applicable / Not specified. This device is an immunoassay, not a machine learning model that requires a "training set" in the conventional sense of AI development. Its performance is based on the chemical and optical design of the lateral flow assay and the internal programming to interpret the signal, which is not typically "trained" on data in the same way an AI algorithm is.
9. How the ground truth for the training set was established:
- Not applicable. As explained above, there's no traditional "training set" for this type of IVD device. The design and calibration are based on established immunochemical principles and reference materials.
§ 862.1155 Human chorionic gonadotropin (HCG) test system.
(a)
Human chorionic gonadotropin (HCG) test system intended for the early detection of pregnancy —(1)Identification. A human chorionic gonadotropin (HCG) test system is a device intended for the early detection of pregnancy is intended to measure HCG, a placental hormone, in plasma or urine.(2)
Classification. Class II.(b)
Human chorionic gonadotropin (HCG) test system intended for any uses other than early detection of pregnancy —(1)Identification. A human chorionic goadotropin (HCG) test system is a device intended for any uses other than early detection of pregnancy (such as an aid in the diagnosis, prognosis, and management of treatment of persons with certain tumors or carcinomas) is intended to measure HCG, a placental hormone, in plasma or urine.(2)
Classification. Class III.(3)
Date PMA or notice of completion of a PDP is required. As of the enactment date of the amendments, May 28, 1976, an approval under section 515 of the act is required before the device described in paragraph (b)(1) may be commercially distributed. See § 862.3.