Studybox Research 510(k) Clinical Studies
Point-of-Care PT/INR Test
Clinical and analytical performance to support substantial equivalence.
Studybox
510(k) Clinical Studies
Point-of-care INR monitoring of warfarin therapy spans clinic testing and patient self-testing at home, and both have waived or home-use precedents. The clinical study is a method comparison against a laboratory PT/INR using a reference thromboplastin, with agreement assessed not just as a regression but in the clinical categories that drive dosing. The known limitation of point-of-care INR is reduced agreement at high INR values, and the study must enroll enough patients above the therapeutic range to characterize it.
Enrollment comes from anticoagulation clinics, where patients on warfarin are seen regularly and INR values span the range, including supratherapeutic values on the day of a dose adjustment. Patients with antiphospholipid antibodies, those transitioning from heparin and those with hematocrit outside the device's range are typical exclusions or separately analyzed groups, because these conditions affect point-of-care PT methods differently from laboratory methods.
- Analyte
- Prothrombin time, reported as International Normalized Ratio (INR)
- Therapeutic area
- Hematology
- Specimens
- Capillary Fingerstick Blood, Venous Whole Blood
- Intended-use settings
- physician office, home use, urgent care, hospital POC, emergency department
- Operators
- Anticoagulation clinic staff, medical assistants and nurses in waived settings; patients or caregivers for prescription home-use self-testing.
- Comparator
- Typically a laboratory PT/INR using a reference thromboplastin with a documented International Sensitivity Index, run on paired citrated venous plasma; a comparison with a cleared point-of-care INR device may be included but does not replace the laboratory reference.
510(k) Studies specifics
What Changes for This Assay on This Pathway.
- The laboratory comparator's thromboplastin and ISI should be documented and the INR calculation traceable; comparing only to another point-of-care device is not a sufficient reference.
- Supratherapeutic INR values must be adequately represented, and the analysis should show agreement at and above the thresholds where clinicians withhold or reverse warfarin.
- Hematocrit range, heparin interference and antiphospholipid antibody effects are specific analytical questions for point-of-care PT methods and are addressed in labeling.
Endpoints the study must support
- Method comparison of INR against the laboratory reference across the therapeutic and supratherapeutic ranges, with agreement in clinical categories (below range, in range, above range)
- Imprecision at waived sites by untrained operators and, for self-testing claims, by patients
- Agreement between fingerstick and venous whole blood on the device
- For home-use claims, lay user agreement with the laboratory reference and labeling comprehension
Enrollment realities
Driven by coverage of the INR range, especially supratherapeutic values, which are a small fraction of anticoagulation clinic visits and must be actively captured. Self-testing arms add training and same-day laboratory logistics.
How Studybox runs it
Pre-Qualified Sites, Embedded Coordinators.
Our 100+ pre-qualified U.S. sites are matched to the intended-use population and setting, with Studybox coordinators embedded on site for recruitment, consent, specimen handling, and data capture. Typical activation is about four weeks. How we run 510(k) clinical studies →
Same assay, other pathways
Relevant FDA guidance
FAQ
Point-of-Care PT/INR Test Study Questions.
01 Who operates the point-of-care pt/inr test in a 510(k) studies study?
Anticoagulation clinic staff, medical assistants and nurses in waived settings; patients or caregivers for prescription home-use self-testing.
02 What is the comparator for a point-of-care pt/inr test study?
Typically a laboratory PT/INR using a reference thromboplastin with a documented International Sensitivity Index, run on paired citrated venous plasma; a comparison with a cleared point-of-care INR device may be included but does not replace the laboratory reference.
03 What drives enrollment for a point-of-care pt/inr test study?
Driven by coverage of the INR range, especially supratherapeutic values, which are a small fraction of anticoagulation clinic visits and must be actively captured. Self-testing arms add training and same-day laboratory logistics.
Let's talk IVD research
Planning a point-of-care pt/inr test study?
Tell us the intended use and setting. We'll come back with a site plan, operator strategy, and a realistic activation timeline for the 510(k) studies pathway.