new INR tester

[Beckysuec]

I have been diagnosed with APS for 25 years after having a stroke at 37 years. My treatment medication treatment regime is warfarin plus baby aspirin. I have my INR completed between 1-3 weeks apart but usually every two weeks due to its variability. I have received a coaguchek INRange point of care tester (POC) to use when I travel. I read that people do comparisons between venous blood labs and POC testing to get an idea about the accuracy but also the differences in reading to assist with determining their INR. I would appreciate people's thought or any tips that they can give me. Thanks

[sailorbaejon]

hi!

I also got my INRange meter a few months ago, ready for a month away in Nepal, consultant was concerned my diet would change and wanted me to test weekly.

Before I could use it regularly I had to do the following:

1) Read instructions and be happy with the machine in general.

2) Attend my Anticoagulant clinic with the machine so they could see it was ok, in good condition / working etc.

3) Take a sample in front of the nurse and then test it on my machine to demonstrate that I could turn it on, follow instructions, put the strip in, do it all within the relevant times etc.

4) The nurse then tested the same blood on the hospital machine (fancy professional one) to make a comparison against my machine.

5) I then had to read and sign a declaration that I would test as and when instructed, and according to machine instructions etc.

6) I have to have a venous test at least every 3 months to confirm, if not more often.

7) I have to take the machine back every 6 months to check the calibration against the clinic machine.

I’m really pleased with it, very quick and simple to use, and saves a lot of hassle getting to clinic on the train etc.

I’ve heard some criticisms of the machines, but basis my consultant and clinic all supportive of it then I’m happy to use it.

Only problem I had was using it in the cold mornings. Had to go back to bed and warm it up for 30 minutes a couple of times!

Hope this all of use, good luck!

Cheers

SBJ

[sailorbaejon in reply to sailorbaejon]

To add….so far when I’ve had venous comparisons the readings are always very close, eg within 0.1 or 0.2, which the clinic are happy with.

Cheers

[Beckysuec in reply to sailorbaejon]

I appreciate your detailed response. I am leading about this system on my own as my involvement in clinic is only for bridging. I thanks you for sharing the information on the comparative readings. That assists me.

[Greenmil3]

I would love to go back to my coagcheck machine but after 2 years did venous comparison and showed wildly inaccurate for me. They are easy to use once you get the hang of it and the ginger prick is so much less hassle than trips to have blood taken. Good luck and enjoy your travels

[Beckysuec in reply to Greenmil3]

Thanks for your information. I hope I am able to successfully use this for travel. Thanks for taking the time to respond.

[MJTroubadour]

Hi there! I have one for travel as well . I am single positive (anticardiolipin) primary in Canada. I have my machine calibrated with my venous draw every 3 months. I am tested once per month at the hospital. From what I understand, not all aps patients are able to use it. It seems to depend on if you're single, double or triple positive and which antibodies you are positive for. Mine has always matched perfectly with my blood draw and in a pinch I might depend on it if for some reason I couldn't get to my regular clinic. The price of the tests is quite steep so I do limit it to travel only. I hope that helps!

[Beckysuec in reply to MJTroubadour]

Many thanks for your reply. I also reside in Canada. It is interesting to hear about the issue with accuracy depending on the degree of positivity. All the information is helpful to me regarding my use of this equipment and what to expect with results. I appreciate you taking the time to respond.

[MJTroubadour in reply to Beckysuec]

Of course! Best of luck. I'm in Ontario... Kingston.

[sailorbaejon in reply to MJTroubadour]

Hi, saw yours about the single / triple diagnosis etc. Do you know when it’s considered possibly unreliable? I’m triple positive, but my consultant still seems happy for me to use it. Must admit, I’m tempted to get a more regular venous comparison done, there’s a lot at stake for not having it right!!

[MJTroubadour in reply to sailorbaejon]

💯!!! I seriously only use it when I am not able to be at my home clinic. I've heard that it is potentially unreliable for some people but like you, my hematologist is the one that recommended it to me and to be fair, it's always been bang on with the venous INR readings. I travel sometimes for a month at a time and since I only get my INR treated once per month, It very rarely gets used. But I think as long as I was confident in my vitamin kind consistency (I weigh and measure all of my vitamin k rich foods and track them in an app), I would depend on it in a pinch till I could get to my clinic.

[sailorbaejon in reply to MJTroubadour]

Yeah, I’m super cautious with keeping my diet as consistent as possible, but when I had a month in Nepal the doc insisted I get the machine, as she was confident (and she was right!) that my food intakes would change. INR went up from around 2.2 to 3.7 probs as I just wasn’t eating any green veg!

[MJTroubadour]

Oh yikes!!!

[GranadaBob]

Hi,

SBJ has provided a thorough description of their Coaguchek use regime and I think the Roche Coaguchek is a wonderful device for most people.

HOWEVER MJTroubadour rightly warns a Coaguchek doesn't give reliable INR readings for everyone.

If you test positive for Lupus anticoagulant, using a Coaguchek machine whilst on Warfarin can lead to inaccurate INR readings. Hence the importance of points 4) and 6) of SBJ's post.

Buried deep within the Roche instructions is this information: "The presence of anti‑phospholipid antibodies (APAs) such as Lupus antibodies (LA) can potentially lead to prolonged clotting times, i.e., elevated INR values."

The FAQ at diagnostics.roche.com/globa... reinforces this.

Specifically, the answer to the question “Are there interferences when testing with CoaguChek systems?” is:

“The presence of anti-phospholipid antibodies (APAs) such as Lupus antibodies (LA) can potentially lead to prolonged clotting times, i.e. elevated INR values. A comparison to an APA-insensitive laboratory method is recommended if the presence of APAs is known or suspected”

I'm triple positive and found out about this Coaguchek limitation the hard way a year ago - it cost me a TIA.

In my case, if the Coaguchek reported an INR around 3.5 (my target INR), a venous draw showed 2.0 or 2.1.

If a venous draw showed 3.5, the Coaguchek reported INR out of range, i.e. > 8