So whom do you trust???

[jeffp]

A while back I posted about having an INR on the PCP's CoaguChek of 6.1. The lab came back with 3.8. My INRatio gave 6.1 (all taken within 30 minutes of each other). Being as the sample sat in the courier's car for most of the day (this was a cooker of a day on August) before getting to the lab and the agreement on both POS units, I tended to lean towards the units vs the lab.
Found this on the FDA site today:
http://www.fda.gov/foi/warning_letters/g5503d.htm
requesting from Hemosense an explantion of why their INRatio has such a large difference from the lab standards.
also see:
http://www.hemosense.com/support/downloads/5500209_INRatio_vs_MLA_WhitePaperRevB.pdf
which is hemosense's testing against the lab equipment.

For me, for now, I'm going with the home testing and have been targeting the higher range of the INR as recommended by my cardiologist.

 

[Karlynn]

Your test experience underscores the popular opinion here that lab results have a much wider unknown that the instant read you get from a Coagucheck, ProTime or INRation machine. You don't know what happens to the lab collection tube once it leaves your sight. Is it tested right away, does it sit in a basket in the lab, how is the sample handled, etc, etc.

Some of us who home test go get a lab test occasionally, in order to see how our monitors are working. I just like to make a comparison between my doctor's machine and mine when I go in for my 6 mo. checkups.

 

[Ross]

I'll take my machine reading any day over the labs, thank you.

 

[Marty]

Lab vs. fingerstick home monitor?

Lab vs. fingerstick home monitor?

I'll take my machine reading any day over the labs, thank you.

An anecdote. About two years ago I asked the lab in my own clinic to test me as I hadn't had a lab test in months. I was self dosing on the basis of my results from a Coaguchek. The lab tech had trouble getting blood from my old fragile arm veins but finally did ( with my help!), bandaged me up, and sent me back to my office across the hall in radiology.About 11:00 AM I got my result-INR 1.2! I had gotten 3.3 earlier on my monitor. At 5:00 PM I was sitting in my office figuring out a new dose schedule when the chief lab tech came in looking flustered. She said ,disregard the reading I got earlier in the day. I asked why? She said and I quote: "trouble with the controls". Our lab uses a great big box to test with the impressive name, Sysmex RCA-1000 coagulation analyser with Dade Inovin thromboplastin and then about 20 control tests. What happened exactly to my test? I never got any more explanation. I totally rely on the little fingerstick now and have had no problems.

 

[Blanche]

Dr. Jeff:
In reading the two sites that you listed, I have, once again, questioned whether or not things are best in the beginning. We seem to know the possible problems with lab testing, but the new machines pose a set of problems all their own. When we get home monitors, our doctors require that we test then against lab results. Perhaps that should require us to test them against the CoaguChek monitor, which has the longest track record for home monitors.
Blanche