(123 days)
The CoaguChek XS System is intended for use by professional healthcare providers for quantitative prothrombin time testing for the monitoring of warfarin therapy. The CoaguChek XS System uses fresh capillary or non-anticoagulated venous whole blood.
The CoaguChek XS is a 3rd generation CoaguChek meter which measures prothrombin time in fresh capillary or non-anticoagulated venous whole blood samples. The CoaguChek XS System incorporates many of the perspectives shared by FDA during reviews of our previous systems, including but not limited to integrated quality control and a blood application area that is outside the meter. The CoaguChek XS System includes a meter and CoaguChek XS PT test strips. Each box of test strips has its own code chip that you insert into the meter. The code chip contains important information about the test strips such as their expiration date and lot number. The meter and test strips work together to provide a safe and reliable system for testing blood-clotting time.
Here's a breakdown of the acceptance criteria and study information for the CoaguChek® XS System, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document compares the CoaguChek XS System to its predicate, the CoaguChek S System, across various performance characteristics. While explicit "acceptance criteria" (i.e., predefined thresholds for success) are not formally stated with numerical targets, the comparison table implicitly defines them by demonstrating performance that is either equivalent to or improved upon the predicate device.
| Performance Characteristic | Acceptance Criteria (Implicit - based on predicate or improved performance) | CoaguChek XS System Reported Performance |
|---|---|---|
| Bilirubin Interference | No significant effect up to 20 mg/dL (predicate) | No significant effect up to 30 mg/dL |
| Hemolysis Interference | No significant effect up to 500 mg/dL (predicate) | No significant effect up to 1000 mg/dL |
| Triglycerides Interference | No significant effect up to 500 mg/dL (predicate) | No significant effect up to 500 mg/dL |
| Hematocrit Range | Not significantly affected between 32 - 52% (predicate) | Not significantly affected between 25 - 55% |
| Heparin Insensitivity | Unaffected up to 2.0 U/mL (predicate) | Unaffected up to 0.8 U/mL* |
| Low Molecular Weight Heparin Insensitivity | Insensitive up to 1 IU anti-factor Xa activity/mL (predicate) | Insensitive up to 2 IU anti-factor Xa activity/mL |
| Capillary Accuracy (vs. Lab Analyzer Plasma) | Correlation (R) of 0.965 (predicate) | Correlation (R): 0.971 (N=700) |
| Venous Accuracy (vs. Lab Analyzer Plasma) | Correlation (R) of 0.970 (predicate) | Correlation (R): 0.974 (N=710) |
| Whole Blood Precision (Venous) | CV = 4.43 (predicate) | CV = 2.42 (N=357) |
| Whole Blood Precision (Capillary) | CV = 7.19 (predicate) | CV = 4.35 (N=344) |
*Note: The heparin insensitivity for CoaguChek XS is lower than the predicate. This is a difference from the predicate, not necessarily an "improvement" in this specific metric. However, the overall device was found substantially equivalent.
2. Sample Size for Test Set and Data Provenance
- Capillary Accuracy: N=700 (combined across all sites)
- Venous Accuracy: N=710 (combined across all sites)
- Whole Blood Precision (Venous): N=357
- Whole Blood Precision (Capillary): N=344
- Data Provenance: The document states that precision was determined from samples collected at "three external sites" for the CoaguChek XS and "five external sites" for the predicate venous blood and "four external sites" for the predicate capillary blood. The specific country of origin is not specified, but the context of an FDA submission suggests studies likely conducted in or compliant with standards in North America or internationally accepted clinical study practices. It refers to "fresh capillary or non-anticoagulated venous whole blood samples," implying prospective collection for the purpose of the study.
3. Number of Experts and Qualifications for Ground Truth
This information is not provided in the given text. The "ground truth" for Prothrombin Time (PT) tests here is a comparison against a laboratory-based reference method, not an expert assessment of images or clinical diagnoses. The reference methods mentioned are:
- Capillary Accuracy: Sysmex Analyzer using Dade Innovin (ISI = 1.02)
- Venous Accuracy: Sysmex Analyzer using Dade Innovin (ISI = 1.02)
- Predicate device comparison: MLA 900 using Ortho Recombiplastin (ISI = 1.03)
These are recognized automated laboratory coagulation analyzers, not human experts.
4. Adjudication Method for the Test Set
This information is not applicable as the ground truth is established by a laboratory reference analyzer, not human reviewers requiring adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
This is not applicable as the device is a diagnostic testing system (measuring prothrombin time), not an imaging device requiring human interpretation for diagnosis. Therefore, there's no "human readers improve with AI vs without AI assistance" scenario.
6. Standalone (Algorithm Only) Performance
Yes, this study primarily assesses the standalone performance of the CoaguChek XS System by comparing its results directly to established laboratory reference methods. The device itself is an automated system, and its output (INR values) is the direct result of its internal algorithm and electrochemical technology.
7. Type of Ground Truth Used
The ground truth used is comparison to a laboratory-based reference method (Sysmex Analyzer using Dade Innovin) for Prothrombin Time (PT) and International Normalized Ratio (INR) measurements. This is considered a highly objective standard for in vitro diagnostic devices like this.
8. Sample Size for the Training Set
The provided text does not specify the sample size for a training set. Given the context of a 510(k) summary, the focus is on performance validation rather than the details of algorithm development (which would typically involve training data). The "CoaguChek XS is a 3rd generation CoaguChek meter," suggesting iterative development, but specific training set details are omitted.
9. How Ground Truth for Training Set was Established
This information is not provided in the document as training set details are not described.
§ 864.7750 Prothrombin time test.
(a)
Identification. A prothrombin time test is a device used as a general screening procedure for the detection of possible clotting factor deficiencies in the extrinsic coagulation pathway, which involves the reaction between coagulation factors III and VII, and to monitor patients receiving coumarin therapy (the administration of one of the coumarin anticoagulants in the treatment of venous thrombosis or pulmonary embolism).(b)
Classification. Class II (performance standards).