Lab vs home testing wierdness

[jeffp]

At my most recent caridologist visit, he wanted to check the INR with a blood draw vs at INRatio (he's not to trusting of the home units). No problem as they were going to stick me for a bunch of other stuff too. Went to my PCP the next morning and he just got a new CoagCheck S for use in the office a few weeks ago ( he never knew they existed until I bitched about getting stuck every week for a while there and told him about my tribulations waiting for my home test unit). The nurse did the calibration and QC stuff just that morning and got reading of 6.3 (no change in my diet or meds, but did stop the exercise the past 4 days due to the weather). I went home and did a test on the INRatio and got 6.2 - close enough to be in agreement. Stopped the coumadin that night and started back as usual the next day. Got the lab results back yesterday and the INR by lab testing was 3.8. Makes me wonder if the home testers are off, but I'm starting to think that the lab results may be off more than we think with transport time in a hot courier vehicle, the skill and care of the busy lab techs, time just sitting in the tube, etc. If I calibrate 3 clocks and one is later off, even if its a bigger fancy clock, I would be hard pressed to rely on it. As a physician myself, I always relied on the labs as the gold standard; I've been rethinking alot of stuff I've taken for granted since the heart surgery.
Hey Al, what's your take?

 

[geebee]

It has been my experience with the INRatio that my lab draws always show an INR lower than the INRatio. I have taken my INRatio to the lab and performed a test immediately after the lab draw. There has been a difference of up to 1.1. However, I have never seen as big a difference as you reported.

I trust my INRatio more than the lab draws because I still occasionally test my SO and he always tests at 1.0 or 1.1.

I think the lab tests sit around which I do believe makes a difference.

 

[Nancy]

Joe has a hematologist for his hemoylsis. They absolutely DO NOT trust lab draws for much. They say it sits around waiting to be transported and then sits waiting to be tested, and it clumps in the tube.

They use their own in office machines and things are done right then and there.

Ask your hematologist at the hospitals where you work and see what they think.

And let us know their opinion.

 

[bvdr]

I trust my ProTime results over lab draws. I know my technique and timing is the same from test to test. My results are consistent and the blood is fresh. Bigger and fancier sure doesn't mean better.

Jeff, I'm glad your PCP got the CoagChek and I think he will be happy with it. My PCP has the same model ProTime tester I use at home and he said he'd never go back to lab draws. That way a patient's dose can be adjusted on the spot. Saves a lot of time and aggravation. I do my own dosing...also saves a lot of time and aggravation .

 

[Karlynn]

Lab tech (vampire) draws your blood, then ships it off to the Keebler Elf, in some tree - for all we know. My Protime and my cards CoaguCheck have usually only differed by a point or two. One time when my INR was low on my machine and w/in range the lab draw, she had me drive into Chicago to her office to run a test on her machine (this was in the early ages of my ProTime). We did the test and threw out the lab results.

 

[Ross]

Just to add my two cents. I tested with a INRatio at 3.6 before leaving home to go to the lab. At the lab, I tested 2.8. This is the second time that I've done this and the difference is usually exactly .6 difference. I'll be doing another here in a couple days only this time, I'm taking the INRatio with me and test at the sametime they draw. I do not trust lab results at all. I have a problem with that, my Doctor is the head of the Lab!

 

[Sherry]

Hi, Jeff,
I just posted a similar scenario in my EEEK...8.0 thread. Coaguchek at the cardio's office was showing 8.0 and the lab down the street (15 minutes later) showed a 5.9. Before this happened, I would typically agree with the business about the blood sitting around for awhile before it gets processed; however, the same lab tech drew my blood and then immediately went over and put it in the machine, which was in the same room. (I watched her do it.) My number was then called to my cell phone by the nurse in 20 minutes. It's just absolutely maddening to be getting discrepancies in our numbers, so I can definitely empathize with you.

 

[EVELYN]

Hi Jeff

Boy can I empathize with you!!! Tyce and I understand exactly where you're coming from. We had, in the past, major problems with the Protime unit we had purchased vs. our cardio's clinic's Coaguchek and the hospital's STAT lab draw. The Cardio's Coagucheck and the lab draw were right on....our Protime..."'s"...(one that we owned and a second that the company sent us to compare ours with and what was happening with it) were waaaay off.

Long story short, we bought a Coaguchek and have been VERY happy since. Tyce tests weekly and we occasionally check ours against our Cardio's clinics.
They're usually right on the money or a tenth of a point off.

I think if you decide to go with a hospital lab draw you have to have the results within 1/2 hour. You can do that if you're in the hospital, but to have to wait for hours to have it processed just negates the entire draw, IMHO.

Evelyn