(127 days)
Clearblue Easy Digital Pregnancy Test is an over-the-counter urine hCG test which is intended for the detection of pregnancy. The test is indicated for use from four days before the expected period.
Not Found
The provided document is an FDA 510(k) clearance letter for the Clearblue Easy Digital Pregnancy Test. It does not contain the detailed study information required to answer your questions about acceptance criteria, device performance, sample sizes, ground truth establishment, or expert involvement. The letter simply states that the device has been found substantially equivalent to a predicate device.
To answer your questions thoroughly, I would need access to the actual 510(k) submission (K060128) which would detail the studies conducted.
However, based on the limited information available in the clearance letter, I can infer some general characteristics of this type of device and the likely studies.
Here's how I can address your request, acknowledging the limitations of the provided text:
Clearblue Easy Digital Pregnancy Test (K060128)
1. Table of Acceptance Criteria and Reported Device Performance
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Acceptance Criteria: The specific acceptance criteria are not detailed in the provided FDA letter. For an hCG pregnancy test, common acceptance criteria typically involve:
- Sensitivity: The lowest concentration of hCG the device can reliably detect (often expressed as mIU/mL).
- Specificity: The ability to accurately detect hCG without false positives from interfering substances or other hormones.
- Accuracy (Agreement): The percentage of agreement with a reference method or clinical outcome.
- Readability/Interpretation: For a digital test, clearly displaying "Pregnant" or "Not Pregnant."
- Early Detection Claim: If the device claims early detection, its performance at low hCG levels (corresponding to days before the expected period) is critical. The letter mentions "use from four days before the expected period," indicating this was a key performance claim.
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Reported Device Performance: The letter only states that the device was found "substantially equivalent" to predicate devices. It does not provide specific performance metrics (e.g., sensitivity, specificity percentages) from Unipath Limited's studies.
| Performance Metric (Likely) | Acceptance Criteria (Typical/Inferred) | Reported Device Performance (Not in document) |
|---|---|---|
| Clinical Sensitivity | High (e.g., >95% at 4 days before period) | Not reported in provided document |
| Clinical Specificity | High (e.g., >99%) | Not reported in provided document |
| Limit of Detection (LoD) | Low hCG concentration (e.g., 25 mIU/mL or less for early detection) | Not reported in provided document |
| Agreement with Predicate | Substantial Equivalence | Met Substantial Equivalence |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: Not specified in the provided document. For an in vitro diagnostic (IVD) device like a pregnancy test, clinical studies typically involve a few hundred urine samples (both positive and negative for pregnancy, often spiked with known hCG concentrations or collected from pregnant/non-pregnant women).
- Data Provenance: The manufacturing company, Unipath Limited, is located in the United Kingdom. It is highly probable that at least some, if not all, of the clinical data was collected from studies conducted in the UK or other European countries, given the company's location. The letter does not specify whether the data was retrospective or prospective. Most clinical validation studies for IVDs involve prospectively collected samples or a combination of prospective and banked retrospective samples.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
- This is not applicable in the traditional sense for a pregnancy test. The "ground truth" for hCG levels is established through quantitative laboratory assays (e.g., enzyme immunoassays, chemiluminescent immunoassays) performed by qualified laboratory personnel, not typically by a panel of clinical "experts" reviewing images or patient cases. The interpretation of the quantitative results would be the "expert" step.
4. Adjudication Method for the Test Set
- Not applicable as the ground truth for hCG levels is quantitative. There wouldn't be an adjudication process among experts for a positive/negative result, as the quantitative gold standard determines the truth.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No. This type of study (MRMC) is generally conducted for diagnostic imaging devices where human readers interpret medical images (e.g., radiologists interpreting X-rays, mammograms). A pregnancy test is an in-vitro diagnostic device that directly detects a biomarker (hCG) in urine. There is no "human reader" component in the sense of interpreting complex visual data that is then compared to an AI algorithm.
6. Standalone (Algorithm Only) Performance Study
- Yes, implicitly. The Clearblue Easy Digital Pregnancy Test is a standalone device. Its performance is evaluated on its ability to detect hCG in urine samples and display a result ("Pregnant" or "Not Pregnant") directly to the user. There isn't an "AI algorithm" in the same way one would refer to it in medical imaging. The "algorithm" here refers to the biochemical reactions and the digital reader's interpretation of the signal produced by the test strip. The clinical studies conducted by Unipath would have assessed this standalone performance.
7. Type of Ground Truth Used
- For an hCG test, the primary ground truth would be:
- Quantitative laboratory hCG values: Urine or serum samples with known, precisely measured concentrations of hCG (determined by a highly sensitive and specific laboratory reference method).
- Clinical outcome: Confirmation of pregnancy via ultrasound or subsequent clinical follow-up for samples from pregnant and non-pregnant individuals.
8. Sample Size for the Training Set
- The document does not provide this information. For a diagnostic device, the "training set" would refer to samples used during the development and optimization phase of the test (e.g., optimizing antibody concentrations, reaction times, digital reader thresholds). This is typically an internal development process, and the sample size is not usually reported in the 510(k) summary, which focuses on validation studies.
9. How the Ground Truth for the Training Set Was Established
- Similar to the validation set, the ground truth for training/development samples would be established using:
- Quantitative hCG reference methods: Accurate laboratory assays to determine the precise hCG concentration in samples.
- Known pregnancy status: Samples from women with confirmed pregnancies (of varying gestational ages) and confirmed non-pregnancies.
This allows developers to fine-tune the test's sensitivity and specificity.
§ 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.