(213 days)
Wondfo One Step HCG Urine Pregnancy Test Strip is a rapid chromatographic immunoassay for the qualitative detection of human chorionic gonadotropin (bCG) in urine, as an aid in early detection of pregnancy, in some cases as early as five (5) days before the expected period, i.e., as early as six (6) days before the day of the missed period. Important note regarding negative results: Some pregnant women will not be able to detect hCG in their urine 5 days before the expected period. If you test negative before your missed period, but think you may still be pregnant, you should test again a few days after your missed period. Important note regarding positive results: Because this test detects low levels of hCG, it is possible that this test may give positive results even if you are not pregnant. If you test positive, but think you may not be pregnant, you should check with your doctor. All results should be confirmed by your healthcare provider, especially when making decisions about future medical care. This product is intended for both prescription use and over-the-counter use.
Wondfo One Step HCG Urine Pregnancy Test Cassette is a rapid chromatographic immunoassay for the qualitative detection of human chorionic gonadotropin (hCG) in urine, as an aid in early detection of pregnancy, in some cases as early as five (5) days before the expected period, i.e., as early as six (6) days before the day of the missed period. Important note regarding negative results: Some pregnant women will not be able to detect hCG in their urine 5 days before the expected period. If you test negative before your missed period, but think you may still be pregnant, you should test again a few days after your missed period. Important note regarding positive results: Because this test detects low levels of hCG, it is possible that this test may give positive results even if you are not pregnant. If you test positive, but think you may not be pregnant, you should check with your doctor. All results should be confirmed by your healthcare provider, especially when making decisions about future medical care. This product is intended for both prescription use and over-the-counter use.
Wondfo One Step HCG Urine Pregnancy Test Midstream is a rapid chromatographic immunoassay for the qualitative detection of human chorionic gonadotropin (hCG) in urine, as an aid in early detection of pregnancy, in some cases as early as five (5) days before the expected period, i.e., as early as six (6) days before the day of the missed period. Important note regarding negative results: Some pregnant women will not be able to detect hCG in their urine 5 days before the expected period. If you test negative before your missed period, but think you may still be pregnant, you should test again a few days after your missed period. Important note regarding positive results: Because this test detects low levels of hCG, it is possible that this test may give positive results even if you are not pregnant. If you test positive, but think you may not be pregnant, you should check with your doctor. All results should be confirmed by your healthcare provider, especially when making decisions about future medical care. This product is intended for over-the-counter use.
Each of the devices (strip, cassette, and midstream) contains a pouch with the test and instructions. The cassette and midstream nitrocellulose test strips are contained in plastic housing. The cassette test also contains a dropper. The strips of each device contain mouse monoclonal anti-β-hCG antibody colloidal gold conjugate pre-dried on the pad, mouse monoclonal anti-u-hCG antibody (on the Test Line) and goat anti mouse IgG polyclonal antibody (on the Control Line).
Here's a breakdown of the acceptance criteria and study details for the Wondfo One Step HCG Urine Pregnancy Test, as extracted from the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state "acceptance criteria" in a tabulated format with pass/fail marks. However, it presents the performance characteristics measured and the results obtained for the device. Based on the information provided, we can infer the performance criteria and the device's reported performance:
| Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|
| Analytical Sensitivity / Cut-Off Value: Ability to detect specific hCG concentrations (critical at 8 mIU/mL and 10 mIU/mL). | Cut-off value: 8 mIU/mL (established) |
| Analytical sensitivity: 10 mIU/mL (established) | |
| Detection Rates: |
- 7.5 mIU/mL: ~28-30% positive across formats and lots.
- 8 mIU/mL: ~50-51.7% positive across formats and lots.
- 9 mIU/mL: ~88.3-90% positive across formats and lots.
- 10 mIU/mL and above: 100% positive across formats and lots. |
| Stability: Maintain performance over time. | Stable at 4-30°C for 24 months (based on accelerated stability at 50°C and real-time stability at 4°C and 30°C). |
| Specificity and Cross-Reactivity: No interference from high hCG concentrations (no hook effect), different hCG fragments (B-core), or other glycoprotein hormones (LH, FSH, TSH). | High Dose Effect: No hook effect observed at hCG concentrations ranging from 6,250 to 200,000 mIU/mL.
Effects of hCG ß-core fragment: No interference observed for urine samples with 0 mIU/mL hCG and 10 mIU/mL hCG (except false negative at 500,000 pmol/L of ß-core fragment hCG, which is a very high concentration).
Effects of glycoprotein LH, FSH and TSH: No interference observed at LH concentrations up to 500 IU/mL, FSH concentrations up to 1000 mIU/mL, and TSH concentrations up to 1000 µIU/mL. |
| Interfering Substances: No interference from various common substances. | No interference observed for all 20 tested compounds (Acetaminophen, Acetylsalicylic acid, Ascorbic acid, Atropine, Caffeine, Gentisic acid, Glucose, Hemoglobin, Tetracycline, Ampicillin, Albumin, B-hydroxybutyrate, Ephedrine, Phenylpropanolamine, Phenothiazine, EDTA, Salicyclic Acid, Benzoylecgonine, Cannabinol, Codeine, Ethanol, Bilirubin, Atropine, Pregnanediol, Thiophene, Ketone) at stated concentrations, for both 0, 10, and 100 mIU/mL hCG samples. |
| Effect of Urine Specific Gravity and Urine pH: Consistent performance across varying urine properties. | No interference from pH ranging from 4 to 9.
No interference from specific gravity ranging from 1.000 to 1.035. |
| Precision: Consistent results across multiple replicates, operators, and lots. | Consistent results across 10 replicates for 5 consecutive days by three different operators at 3 POC sites, using 3 different lots for each format, for hCG concentrations ranging from 0 to 50 mIU/mL. E.g., for 10 mIU/mL, all 50 replicates were positive across all 3 lots for all formats. For 0, 2.5, 5 mIU/mL, all 50 replicates were negative across all 3 lots for all formats. The detection rates for 7.5 mIU/mL and 8 mIU/mL show expected variability around the cut-off. |
| Method Comparison with Predicate Device: High agreement with a legally marketed predicate device. | 100% agreement for both positive and negative samples when compared to the FIRST RESPONSE™ Early Result Pregnancy Test (K123436) for all three device formats (Strip, Cassette, Midstream). |
| Lay Person Study: Ease of use and accuracy when used by intended lay users. | Overall Agreement with Professional: - Strip: 100% agreement (49+/51- vs 49+/51-).
- Cassette: 99% agreement (48+/51- vs 48+/52-), with 1 false positive by lay person.
- Midstream: 100% agreement (49+/51- vs 49+/51-).
Correctness for Spiked Samples (5mIU/ml, 10mIU/ml): - Strip: 99% for 5mIU/ml (1+/99-), 100% for 10mIU/ml (100+/0-). (Note: The table on page 13 for strips and 5 mIU/mL seems to have a typo, showing 1 positive for 5mIU/mL. The overall result for lay person vs professional for strips is 100% agreement, which contradicts the 1 positive result for 5mIU/mL in the next table. Assuming the professional comparison is the primary indicator of overall accuracy vs ground truth).
- Cassette: 100% for 5mIU/ml (0+/100-), 100% for 10mIU/ml (100+/0-).
- Midstream: 100% for 5mIU/ml (0+/100-), 99% for 10mIU/ml (99+/1-).
Consistency for Spiked Samples (7.5mIU/mL, 8mIU/mL): - Strip: 96% and 97%.
- Cassette: 96% and 96%.
- Midstream: 96% and 97%.
Ease of Use: All lay users indicated instructions were easily followed. Flesch-Kincaid reading Grade Level of 7 for package inserts. |
| False Positive Rate: Low rate of positive results in non-pregnant individuals. | Strip: 0.3% false positive results (1 false positive out of 300 non-pregnant females, from a peri-menopausal woman confirmed non-pregnant via ultrasound).
Cassette: 0.3% false positive results (1 false positive out of 300 non-pregnant females, from a peri-menopausal woman confirmed non-pregnant via ultrasound).
Midstream: 0% false positive results (0 out of 300 non-pregnant females). |
| Early Pregnancy Detection: Ability to detect pregnancy early relative to the Expected Menstrual Period (EMP). | Detects: - 68% positive hCG five days before EMP.
- 100% positive hCG on the day of EMP.
- Performance consistent across device formats. |
| Substantial Equivalence: Overall performance comparable to the predicate device. | Concluded to be substantially equivalent to the predicate device (Church & Dwight Co., Inc. FIRST RESPONSE™ Early Result Pregnancy Test). |
2. Sample Size Used for the Test Set and Data Provenance
- Analytical Performance (Sensitivity/Cut-Off, Interference, Precision):
- Sensitivity/Cut-Off: 20 replicates per hCG concentration level per lot (3 lots), tested by 12 operators. This means 60 tests per hCG level per format (e.g., for Strip format: 60 tests for 0mIU/ml, 60 for 5mIU/ml, etc.). The study used Urine standards containing intact hCG calibrated against WHO 4th IS for hCG. The provenance is not explicitly stated but is implied to be laboratory-prepared standards.
- Specificity & Cross-reactivity: Samples (negative urine and 10 mIU/mL hCG) spiked with specified interfering substances. Each spiked sample was tested by 3 different lots and 3 different operators. The exact number of replicates per sample/condition is not explicitly stated, but for each interfering substance, a series of tests were done to ensure no interference.
- Precision: 10 replicates per day for 5 consecutive days using 3 different lots for each format. This means 50 tests per hCG concentration per lot per format (e.g., for Strip format, 50 tests for 0mIU/ml, 50 for 2.5mIU/ml, up to 50 for 50mIU/ml, for each of the 3 lots). Tests were performed by 9 POC operators (3 for each format). The ground truth was negative human urine samples spiked with varying hCG concentrations (commercially available and traceable to 4th WHO international standard). Provenance is likely laboratory-prepared.
- Method Comparison with Predicate Device:
- Sample Size: 100 urine samples for each format (total 300 samples).
- Provenance: Collected from 100 women (about half pregnant, early stage at less than 5 weeks). Samples randomly collected at various times throughout the day. Ages ranged from 20 to 45 years. The provenance is clinical/human samples, seemingly prospective (collected for this study given the blind labeling and specific testing procedure). Country of origin is not specified.
- Lay Person Study:
- Sample Size: 100 lay persons for the strip devices, 100 for the cassette devices, and 100 for the midstream devices (total 300 lay persons).
- Provenance: For samples with known hCG concentrations, urine samples were prepared at 5mIU/ml, 8.0mIU/ml, 8.0mIU/ml hCG by spiking hCG into negative pooled urine specimens (laboratory-prepared). Additionally, each participant tested "her own urine sample" (clinical/human, self-collected). Provenance for lay users is diverse educational and professional backgrounds, aged 21 to >50 years, likely within the location of the study (not specified).
- False Positive Rate Study:
- Sample Size: 300 non-pregnant females for strip, 300 for cassette, and 300 for midstream (total 900 non-pregnant female tests).
- Provenance: Non-pregnant females who tested "their own urine samples" (clinical/human, self-collected). Provenance likely within the location of the study (not specified).
- Early Pregnancy Test Study:
- Sample Size: 585 urine samples from 65 characterized cycle segments of conceptive cycles were collected from 65 pregnant women.
- Provenance: Clinical/human samples from pregnant women.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Analytical Performance:
- Sensitivity/Cut-Off: 12 operators tested each standard. Qualifications not specified, but likely laboratory technicians given the nature of the testing.
- Specificity & Cross-reactivity: 3 different operators. Qualifications not specified, but likely laboratory technicians.
- Precision: 9 Point-of-Care (POC) operators (3 different operators for each of 3 formats). Qualifications not specified, but suggests healthcare professionals.
- Method Comparison with Predicate Device:
- Ground Truth: The "predicate device" serves as the reference standard.
- Testing Personnel: 9 POC operators (three different health professionals at each of the 3 POC sites). Qualifications of "health professionals" not specified but implies skilled personnel.
- Lay Person Study:
- Ground Truth: Professional testing of the same samples.
- Testing Personnel: "Professional" testing results are compared to lay person results. The qualifications of these professionals are not explicitly stated, but it is implied they are trained individuals capable of accurately interpreting the test results.
- False Positive Rate Study:
- Ground Truth: Derived from professional testing and, in some cases, ultrasound scan confirmation for the false positive results.
- Testing Personnel: The results were from the non-pregnant females themselves, but the ground truth was also established by professional testing and, for the identified false positives, confirmed by ultrasound.
- Early Pregnancy Test Study:
- Ground Truth: "Characterized cycle segments of conceptive cycles" from pregnant women indicate clinical diagnosis of pregnancy (likely through follow-up serum hCG, ultrasound, or confirmed delivery/outcome).
- Testing Personnel: Tests were done by an unspecified number of individuals using all three formats. Implicitly, clinical professionals would have characterized the cycle segments.
4. Adjudication Method for the Test Set
The document does not explicitly describe a formal adjudication (e.g., 2+1, 3+1) method for conflicting interpretations of test results within the studies. Observations:
- Analytical Performance (Sensitivity/Cut-Off, Interference, Precision): For the sensitivity/cut-off and precision studies, results are reported as aggregates from multiple tests by multiple operators. It appears individual operator results were combined (e.g., 10-/10+ implies 10 negative, 10 positive results out of 20 by various operators). There's no mention of a consensus process for discrepant results at the individual reading level.
- Method Comparison and Lay Person Studies: These studies compare the device results to either a predicate device or professional results. The "Professional" results are presented as a single ground truth, implying any potential disagreements among professionals for the ground truth were already resolved or not present.
- False Positive Rate Study: For the two cases of false positives, an ultrasound scan was used for confirmation, which serves as a higher-level adjudication for those specific ambiguous cases.
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 was not performed in the context of AI assistance. This document describes a medical device (pregnancy test strips/cassettes/midstream) that is a rapid chromatographic immunoassay, not an AI-powered diagnostic tool. Therefore, the concept of "human readers improve with AI vs without AI assistance" is not applicable here.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This is not applicable, as the device is a manual, qualitative immunoassay. There is no algorithm or AI component. The user (human-in-the-loop) visually interprets the results.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The type of ground truth varied by study:
- Analytical Performance:
- Sensitivity/Cut-Off, Specificity, Interfering Substances, Precision, Urine Properties: Laboratory-prepared hCG standards (calibrated against WHO 4th IS for hCG) in negative urine pools, or negative urine samples spiked with known substances. This represents a highly controlled and quantitative ground truth.
- Method Comparison with Predicate Device:
- The predicate device (FIRST RESPONSE™ Early Result Pregnancy Test) served as the comparative ground truth.
- Lay Person Study:
- Professional testing results of the same samples. For samples with known hCG concentrations, the prepared hCG concentrations served as ground truth.
- False Positive Rate Study:
- Confirmed non-pregnancy status (e.g., patient history, and in specific false positive cases, confirmed by ultrasound scan).
- Early Pregnancy Test Study:
- Characterized conceptive cycles from pregnant women. This implies clinical confirmation of pregnancy based on biological outcomes (i.e., actual pregnancy).
8. The Sample Size for the Training Set
This document describes performance studies for an existing medical device, not the development or training of an AI algorithm. Therefore, there is no "training set" in the context of machine learning. The studies described are validation and verification studies for the device's performance.
9. How the Ground Truth for the Training Set Was Established
As there is no training set for an AI algorithm, this question is not applicable.
§ 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.