Coagucheck testing methods

Some time ago we had some discussions about wasted strips due to failure of method and I promised to report back on the test I have at my surgery. Had one yesterday so here goes. (2.7 by the way after a week of antibiotics).

I asked the phlebotomist how she did it and was amazed at what she told me. The blood does not go on top or underneath. She inserted the strip after stabbing my finger and then holding the machine in one hand and my hand in the other scraped the blood off by moving the strip over my finger from one side to the other. She explained that the strip has a tiny gap between top an bottom sections and the blood needed to get into this gap for the test. When I asked about dripping the blood on top she said it can get into the strip but it is not a fool proof way, which her method is. Now I understand why I thought you put the blood on the underside as that is what it looks like from my angle when she does it.

So people now you know. I hope that this helps some of you to stop wasting strips so often as reported.


18 Replies

  • Thanks for this Bob. I have copied and pasted for future reference. I am in limbo on the self testing front. My surgery seemed keen but the idea went off the boil somehow and I am not that keen to fork out almost £400. My INR is at least consistent at 2.0 and although I think the level is inadequate especially as I am taking vast quantities of warfarin a week (currently 66mgs) I'm just drifting along for the time feeling mildly peeved about it. I don't have a lot to complain about. I'm off on a jolly in two days and would not have been brave enough to even contemplate it a year ago.

  • I have a feeling there are moves afoot on self testing so watch this space.


  • Rellim, I was on 10 mg daily at one point but am now on around the 6mg dose and have been for some time. Don't know what happened! It didn't bother me ,I just made sure I had frequent testing. Sandra

  • I'm the other way round. I once had an INR of 2.0 when on 8mgs but then I dropped to 1.6 and now I'm at 2.0 on 3 x 10mgs and 4 x 9mgs. Monthly checks are fine they say and I should not fuss.

  • When I use my Coaguc Chek kit I always collect the blood onto the side of the strip , slightly under, & it invariably gets ' taken up ' straight away. I wasted alot of strips trying to drop the blood on the top part.


  • You got it! Shame there hasn't been more training on this . I had to make a special point of stopping the lady in her tracks and asking for a step by step guide as we had all that discussion some while back.


  • I had the same problem when I first started with my machine and wasted quite a few test strips before I had the sense to notice and then ask my "blood nurse" why she appeared to be taking the blood in a different way to me, I was trying to follow the step by step guide and DVD that came with my machine.

    Thankfully I followed her advice on the way she had been taught to use it and have had very few problems since.

    I have spoken to Roach about this but I don't know if they have made any adjustments to the instruction manual yet.

    Bob, I think I would have struggled to put it as plainly as you, well done.


  • I think that theCoaguChek instructions are hopeless! It didn't help that I also had a dodgy machine which had to be replaced. I was beginning to think that I had wasted £300 !

  • When i was self testing I tried both ways but if I touched the strip it came up as error 5. Yet when the nurse actually held my finger on the strip yesterday it was fine.

  • Hi Barb1,

    With the earlier CoaguChek you hadn't to touch the strip or you got an error. With the CoaguChek XS the recommended method is to touch the side of the strip, as long as you take your finger away when you hear the beep.


  • Thanks Bob. I think Ive only ever had 2 strips error out on me in the past 3 years. But I like to ensure I have the unit on a flat level surface when performing each test. If I have another error out on me I wont throw it away and Ill try your method as described. Anyhow, gotta give myself a clexane injection right now lol. You know how it is post surgery... getting back on the Warfarin again lol.

  • Oh I just pool a drop of blood on my fingertip and vertically lower my finger toward the gap in the strip. As soon as the blood drop touches the strip it fills the gap and collects fine. You need to have a decent droplet of blood. Too little blood and it will error. Not having the unit on a hard flat surface can cause it to error too.

  • I do the same. Since I started getting the blood from my right hand finger(s) (dominant hand), I've had no errors.

  • I do exactly that too .... no problems with wastage ever.

  • Hi Bob,

    That's what the instructions for the CoaguChek XS test strips says. The blood can be applied on top or to either side. I apply it to the side since I then don't need to drip the blood on top. Just squeeze the finger and touch the side of the strip with the blood that's oozing out. Still waste the occasional strip if my INR has gone too low, around 2.0, and the blood doesn't come out as easy.


  • I have the XS but maybe I wasn't moving my finger away as soon as it beeped. As for keeping it on a level surface the nurse moves it around freely and no error. Anyway I cannot self test at the mo, as GP does not allow.

  • Watch this space.

  • I'm Watching!!

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