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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Validation

Feb 13 2013

george

More on PT Validation and AMR

Here’s an additional note confirming Denise Solieau’s February 12 discussion of PT validation and analytical measurable ranges (AMRs). Page 83 of the July 31, 2012 CAP survey references the value of AMRs in coagulation testing and includes this statement, “The new checklist requirements (meaning AMR) apply to hemostasis test methods that are calibrated and directly measure the concentration or […]

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Anticoagulant Therapy

Oct 25 2012

george

AMR: Matrix-appropriate Materials

From Purvi Jariwala, Texas Children’s Hospital: Hi George, There is a new CAP checklist requirement published 7/31/2012. Heme.38009 AMR validation: “Validation of the analytical measurement range (AMR) is performed with matrix-appropriate materials, which include the low, mid and high range of the AMR.” I wanted to post this on your site to see how other laboratories will be addressing […]

Validation

ASCP Statistics and QC Workshop

Thanks to those who attended our American Society of Clinical Pathology Laboratory Statistics and Quality Control workshop on Friday, October 5 in Minneapolis, MN. I hope we met your needs. As promised, I’ve attached 6-per-page PDFs of my first and last lectures, Pre-analytical and Post-analytical Variables. These are the lectures that contained updated slides not provided in your […]

Validation

Normalized DRVVT Ratio?

George has had several conversations with frequent contributor and international expertDave McGlasson (Wilford Hall USAF Medical Center, San Antonio) about normalizing the DRVVT ratio on the laboratory’s DRVVT mean of the reference interval in accordance withZhang L, et al: A simplified algorithm for the laboratory detection of lupus anticoagulants. Am J Clin Pathol 2005;124:894–901. The author […]

Lupus Anticoagulant

How to Validate an Aggregometer

From Rrosales: I am interested in purchasing a platelet aggregometer for our hematology lab, but we don’t have an existing instrument to compare it with. Some suggested H58 NCCLS (CLSI, does not really help) but I am used to validating an instrument with an old instrument (comparison/parallel testing). Can you tell me how to start the […]

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Platelet Function Testing

Apr 30 2012

george

Fibrinogen Assay Reportable Range

Dear George, I am using an STA Compact from Diagnostica Stago. I would like you to throw some light on validating the reportable range of the fibrinogen assay which is 60–1200 mg/dl. How can I obtain plasma with such high levels of fibrinogen? Regards, Dr. Shabnam Roohi. Hello, Dr. Roohi. For assistance I went to Dr. Ali […]

Factor Assays

Quick Question Summary: LDTs

Here is a summary of our April, 2012 Quick Question: The US FDA is planning guidelines for regulating laboratory-developed tests (LDTs). What plans have you made in response? a. We are discontinuing all LDTs: 3 (15%) b. We didn’t know this is happening: 11 (55%) c. None, this will only apply to reference laboratory LDTs: 1 (5%) […]

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Quick Question Archive

Apr 24 2012

george

POC: When to Validate High INRs

George received this question from an anticoagulation clinic coordinator last week: What value would you suggest to repeat a high fingerstick INR to a venous blood, >4.0, >5.0, etc. and why? Thank you. Here is the answer George provided: “Hello, and thank you for your question. Point of care (POC) instruments provide rapid PT/INR turnaround […]

Validation

Normal Plasma Storage

Here is a seemingly simple request from Vicki Lanigan at Niagara Health, Ontario, Canada: “I am looking for a reference for storage of normal pooled plasma (NPP, pooled normal plasma, PNP).” Vicki, this one drove me back to the books and to the package inserts for distributors Precision BioLogic Inc and George King Bio-Medical, Inc to learn the shelf life for […]

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Specimen Management

Validation

Reference Range Change Limit

More on PT Validation and AMR

AMR: Matrix-appropriate Materials

ASCP Statistics and QC Workshop

Normalized DRVVT Ratio?

How to Validate an Aggregometer

Fibrinogen Assay Reportable Range

Quick Question Summary: LDTs

POC: When to Validate High INRs

Normal Plasma Storage

George Fritsma MS MLS

Cheat Sheets from George

Questions or Comments?

Quick Question