Validation

Effect of HCT on POC INR

George received this question from the ASCLS Consumer Web Forum via Bonnie Jo Taylor, MHS, MT(ASCP)SH. I have hemochromatosis, too much iron in my blood. I’ve also had blood clots in my lungs. I peroidically undergo phlebotomy treatments to lower iron count. Will this alter the results of my INR finger prick test results? Here […]

Anticoagulant Therapy

Pediatric Reference Intervals

From Dr. Jasmina Ahluwalia: Dear George, I wonder if you could help me. Is there is a recent reference range available for the pediatric population for the coagulation screening tests, factor assays, protein C, protein S and antithrombin assays on the ACL TOP systems? I did come across one on the STAGO and Sysmex systems […]

Coagulation Factors

FDA Registration

Message from “Ray:” How can companies run ads for non-cleared or approved devices that say “FDA registered?” Thank you, Ray, This issue comes up from time to time, and we addressed it in a March 13, 2015 post. FDA registration does not necessarily imply that a device is approved or cleared, as defined in this […]

How Often to Compute Uncertainty Data

Hello George, I am trying to find an article that tells how often I have to calculate the uncertainty for coagulation assay (fibrinogen, PT, APTT). Can you give me a resource for information or any further help with this? Best regards, Monica Truta, Clinical Laboratory Technician, Infectious Diseases Hospital “Dr. Victor Babes,” Romania. Hello, Ms. Truta, and thank […]

FDA Registration

I’m posting this message at the request of a colleague. “George, I’m told by one of my suppliers that their products are US FDA registered. Does this mean the FDA endorses the company and its products?” Thank you for your question. FDA terminology may sometimes be complex and has perhaps confused your supplier’s representative. The […]

Instrumentation

AACC “Quick Takes” on Quality Assurance

Join George as he kicks off the American Association of Clinical Chemists (AACC) Quick Takes webinar series with “Quick Takes on Quality Assurance in Hemostasis.” George will present three 30-minute presentations on August 7, 14, and 21, 1–1:30 EDT. He will discuss: Employing local calibration for prothrombin time/international normalized ratio (PT/INR) monitoring of Coumadin therapy. Specimen management […]

Reagent and Instrument Variability

From Odetta Hanna, Coagulation Applications Specialist at Sekisui Diagnostics: I was wondering if you could help me locate references or resources to support a statement that I made for Method Comparison: Coagulation: Interpretation of results. I am writing a method comparison procedure and I referenced CLSI EP09-A3. However, I cannot locate any specific supporting documentation for the statements listed […]

What is an LDT?

From Kelly Townsend, Tri-core Reference Laboratories, Albuquerque. Looking for opinions on what constitutes a “Laboratory Developed Test” in Coag. Obviously if the reagent kit is not FDA-cleared, it will be an LDT, but what about factor assays, etc where there is no real kit. What if you are using a kit with a different calibrator or control […]

Delta Checks

From Julia Nailling: What delta checks do laboratories commonly use for autoverification of prothrombin time with international normalized ratio (PT/INR), partial thromboplastin time (PTT), fibrinogen, and D-dimer? Hi, Julia, thank you for your question. I’ll let our participants respond to this, as our own laboratory doesn’t use autoverification or delta checks, although we do carefully inspect […]

Reference Range Change Limit

Maria Grana writes, Hello George, what would constitute a “significant change” when performing the yearly reference range study for coagulation? Thanks. Hello, Maria, and thank you for your question. The laboratory director and staff often establish an acceptable reference range (reference interval, normal range) change limit, beyond which it is necessary to publish a new interval. […]

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George Fritsma is a medical laboratory scientist, educator, and author. George holds faculty appointments with Rutgers University and Michigan State University, and is a member of the International Society on Thrombosis and Hemostasis, American Association of Clinical Chemists, and American Society for Clinical Laboratory Science.

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