How accurate are portable INR test machines?

Posted , 5 users are following.

Early morning trip to clinic with dad. Urine very dark. Strip test

was OK. Nurse explained that its not uncommon when taking

Sintron. B/p was also OK.

Nurse did INR check to be on the safe side. 1st was 6+; 2nd was 5+ & 3rd was 2.9. They put the first 2 readings down to the


How accurate/reliable are these?

Any thoughts would be appreciated.

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10 Replies

  • Posted

    I bought a Roche Coaguchek device 18 months ago. Best thing I ever did. My INR is unstable but when it is within range for a couple of weeks the GP's computer programme says retest in 4 weeks. In that time I can go dangerously out of range. I check myself every week and make small adjustments to the Warfarin dosage to stay more or less on target. I travel a lot and this is so convenient.

    Every time I have a venous check it is accurate to 0.1 or .2. I am very happy with this as is my Cardiologist. I have a mechanical heart valve and my target INR is 3 and the safe range is 2.5 to 3.5.

    Although I paid £300 for the machine I get the test strips on prescription. These would cost £150 a year if I had to pay for them.

    Hope this helps.

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    • Posted

      Thanks for replying.

      As dad is taking part in a hospital trial, I think home monitoringand home adjustment of dosage would be unwise.

      I just wondered how accurate these hand-held machines were.

      The nurse said to continue with the prescribed dose till the

      next scheduled blood test, unless he has any problems.

      He had 2 small ear bleeds last week (he said he poked and it!) got it checked anyway.

      I will ask about these home testers at the next visit.

      (Dad had an ICD fitted Oct '15 & his 6 week post op check

      detected AF)

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  • Posted

    I bought my Roche CoaguChek in  2011 - best thing I ever did.   Being able to self monitor INR, particularly when there might be interaction with other medication, is reassuring.

    ​Usually the advice is that  anti-coagulants should be taken at the same time each day and preferably not at the same time as any other medication. I take Phenindione in the evening and do my INR test first thing in the morning.  


    I rarely attend the INR clinic at the surgery now but, when I do, I take my own reading before leaving home and comparison with the clinic and hospital readings have always shown my CoaguChek to be accurate and reliable. 

    I wish your Dad well

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    • Posted

      Thank you for replying.

      I'll keep the Roche CoagCheck in mind as you're the second. person to recommend it. Once I know Dad will remain on the

      Sintron I'll see about getting one.

      The nurse, today, mentioned his other meds (9) & that some may interact. I've been through this with his doctor & he seem happy.

      As long as Dad feels OK we'll carry on as prescribed.

      He's on restricted activities following his ICD, can't drive his. tractor!

      (he had a triple bypass when he was 60 & has been fit & well till recently)

      Thanks again

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  • Posted

    Hello . Sintrom active ingredients are very similar to Warfarin and may well be the same drug but different brand names . I use my own " Coaguchek " INR meter because the test strips are available on prescription in UK. When regularly calibrated my meter is only .01 down from the official NHS equivalent so is as accurate as possible . I have researched and printed my own guide that keeps me consistently within 2.0 and 3.0 parameters , there are 13 pages of foods , liquids , natural treatments , medical drugs etc .,that interact with Warfarin . My advice is take the prescribed dosage strictly each day or as advised ,keep alcohol as low as possible and do not binge on any source likely to affect INR readings .
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    • Posted

      Good advice thank you.

      I'd be grateful for any pointers regarding food & liquids.

      I always cook from scratch & need to get familiar with what foods are ok & what aren't. Dad does not drink, so alcohol isn't an issue.

      As I said before, Dad is taking part in a hospital trial & his docs are still trying to establish the correct dose to maintain an INR of 2-3. Home monitoring is worth considering. We are lucky that we can go to a local clinic (15 min drive) for blood tests. rather than 'his' hospital 50 mins away. I can't fault the care the has received.

      This is all new to us & is quite daunting.

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  • Posted

    The coaguchek machine is the best thing we bought when my husband was on warfarin...his INR was all over the place and we could keep a much closer check on it with regular tests. So easy to use.
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    • Posted

      Thank you.

      Home monitoring seems a good idea, I'll definately look into it, once things have settled down.

      Dad has great faith in the medical staff - he does everything they him, to the letter. But does not want to know too much. detail regarding his treatment & meds - that's down to me.

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    • Posted

      Sounds like my husband...I took the tests for him and made sure he was taking the right amount to be stable. Its surprisingly easy to do with common sense.

      It makes it so much easier on you as well, as you won't be having to take him for tests every five minutes...its all done in the comfort of your own home.

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    • Posted

      Dads blood tests today - INR 5.1& 4.9! Was hoping for 2-3. After hospital consult decision was to reduce dose to 5g over 7 days for 14 days then re-test.

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