(34 days)
The modified Fact PLUS Pregnancy Test (Cup and Dropper) is an over-the counter in vitro diagnostic immunoassav intended for the qualitative detection of human chorionic gonadotropin (hCG), in urine. A labeling modification to the currently marketed Fact PLUS® Pregnancy Test enables the test results to be read in three minutes or less without altering the accuracy, sensitivity or specificity of the test.
The Fact PLUS Pregnancy Test is indicated for consumer use to detect pregnancy as early as first day of a missed period, any time of the day. Negative test results are confirmed after three minutes, some positives results can be read as soon as one minute.
The modified Fact PLUS Pregnancy Test is a disk-shaped ("Test Disk") device constructed of two pieces of molded plastic. The test chemistries are coated on a test strip housed within the test disk. The test strip contains three reactive sites: a conjugate site, an antibody site and a control site. Three openings on the upper surface of the test disk correspond to these sites: "Urine Well," "Result Window," "Control Window" (CW) respectively.
When urine is added via the Urine Well it wets the conjugate (anti-α hCG antibody) mobilizing it. If hCG molecules are present in the urine specimen, an hCG/conjugate complex is formed. This complex and any remaining unbound coniuqate migrate along the strip attaching to the anti-8 hCG antibody contained on the vertical bar (positive) and also to the polyclonal antibodies on the intersecting horizontal bar (negative) causing a pink reaction. The appearance of pink color on the horizontal and vertical bars forms the "plus" sign or positive "pregnant" result.
When no hCG molecules are present in the urine specimen, the conjugate remains unbound and attaches only to the horizontal or "minus" bar causing it to turn pink. The appearance of only one pink horizontal bar constitutes the negative or ("not pregnant") result.
The urine flow continues on to the Control Window where it activates a special dye causing a red color to appear. The red color in the CW tells the user the that enough urine was added. It is can also play an important role in helping the Consumer Service representatives on our toll free number to evaluate consumer reported problems. It takes approximately five minutes for the urine to reach the Control Window. The appearance of a "plus" or a "minus" in the Result Window however, appears sooner usually within three minutes or less. Some positive results can appear as soon as one minute. The appearance of a plus or minus in the Result Window and red color in the Control Window are the built-in controls which indicate the test chemistries worked properly and that a sufficient volume of urine was added.
Here's an analysis of the provided text regarding the Fact PLUS® Pregnancy Test, broken down into the requested sections:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are not explicitly stated as numerical thresholds (e.g., "sensitivity must be >95%"). Instead, the study aims to demonstrate "substantial equivalence" to existing, marketed devices in terms of accuracy, sensitivity, and specificity. The reported performance is 100% agreement.
| Acceptance Criterion (Implied) | Reported Device Performance |
|---|---|
| Accuracy (against existing Fact PLUS Pregnancy Tests) | 100% agreement |
| Sensitivity (against existing Fact PLUS Pregnancy Tests) | 100% agreement |
| Specificity (against existing Fact PLUS Pregnancy Tests) | 100% agreement |
| Consumer Accuracy (Interpreting results with modified instructions) | 100% agreement |
2. Sample Size Used for the Test Set and Data Provenance
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Laboratory Validation Testing (Accuracy, Sensitivity, Specificity):
- Sample Size: Not explicitly stated as a distinct number of specimens for the main laboratory validation. It mentions "hCG-positive and hCG-negative female clinical urine specimens" and testing across "three different lots of Fact PLUS Pregnancy Test and one lot of Fact PLUS One Step." This implies multiple specimens per lot, but a total count is not given.
- Data Provenance: Retrospective (clinical urine specimens). The country of origin is not specified, but it can be inferred to be the US given the 510(k) submission.
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Consumer Testing:
- Sample Size: 150 evaluable female volunteers (152 enrolled, 2 dropped due to protocol violations).
- Data Provenance: Prospective (recruited for the study). The location was "Central New Jersey."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
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Laboratory Validation Testing:
- Number of Experts: Not specified. The ground truth for hCG-positive and hCG-negative urine specimens would likely be established prior to the study using a reference method, but the text doesn't detail this.
- Qualifications: Not specified.
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Consumer Testing:
- Number of Experts: Not applicable in the same sense as laboratory ground truth. The "ground truth" for this part of the study was whether the provided urine sample was indeed hCG-positive or hCG-negative, which was controlled by the study design (i.e., participants were given "randomized hCG positive or hCG negative urine sample"). The subjects themselves were the "interpreters" whose accuracy was being measured against this known truth.
4. Adjudication Method for the Test Set
- Laboratory Validation Testing: Not explicitly stated. The "100% agreement" implies a direct comparison, likely by trained laboratory personnel. There's no mention of an adjudication process like 2+1.
- Consumer Testing: No formal adjudication process among consumers is described. Each consumer performed the test and recorded their own result, which was then compared to the known status of the urine sample they received.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This study focuses on the device's performance standalone and its interpretability by consumers, not on comparing human readers' performance with and without AI assistance. The device is the diagnostic tool in this context, not an AI assisting human readers.
6. Standalone Performance Study
Yes, a standalone performance study was done.
- Laboratory Validation Testing: This section ("Performance Data") describes the device's accuracy, sensitivity, and specificity in detecting hCG in urine specimens, comparing the modified reading time to the original. This is a standalone assessment of the device's performance.
- Consumer Testing: While involving human interaction, the "consumer accuracy rating" of 100% demonstrates the standalone performance of the device with the modified instructions when used by the intended lay user.
7. Type of Ground Truth Used
- Laboratory Validation Testing: The ground truth was established by classifying clinical urine specimens as "hCG-positive" or "hCG-negative." This would typically be determined by a reference laboratory method (e.g., a highly sensitive immunoassay) considered the gold standard for hCG detection. The text doesn't specify the exact method but implies established clinical classification.
- Consumer Testing: The ground truth was based on the known status of the urine samples provided to the volunteers (either hCG-positive or hCG-negative, as controlled by the study design).
8. Sample Size for the Training Set
Not applicable. This device is a diagnostic immunoassay, not an AI/ML device that requires a training set in the conventional sense. The "training" of the device is inherent in its chemical design and manufacturing process.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set for this type of device.
§ 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.