Blood test for I.N.R. no.: Do all members... - AF Association

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Blood test for I.N.R. no.

feejbee profile image

Do all members have a full blood test each time they go and have their INR no.checked or does anybody have testing via a finger prick of blood like diabetic monitoring.

I know this is available if you self check but wondered if it's done professionally .Are both methods as accurate as each other and if they are why is it necessary to still do full blood tests which I'm sure most of us hate or at least dislike.


40 Replies

Hi Fi

Blood is taken at surgery and sent to the hospital and then I phone the surgery for the result the next afternoon.

Finger prick would be so much quicker - not sure how accurate they are. Would be useful if meds changed or if additional meds needed for a week - to quickly see how INR level is affected.


I have my INR calculated by the "finger prick" method at my local surgery. A related computer programme is given the machine reading and immediately shows if there is any requirement for dosage adjustment. At the outset I questioned the reliabilty of this method and was assured the machine is regularly calibrated so there is no danger of any result inconsistency. The benefit of the "finger prick" method means there is no waiting for results ( and battling to get through on the phone to the surgery!).

I have exactly the same INR test at my surgery as Langara.


vovvarna2 profile image
vovvarna2 in reply to Langara

Same here :-) Quick, in every respect.

I'm checked by the practice nurse, finger prick and coaguchek machine, instant result. Every 25th person tested has blood sent to lab as well to ensure machine is calibrated OK. So far I haven't drawn the short straw for that. I know that some surgeries have a computer programme for working out the amount of Warfarin needed but I have a phone call later the same day telling me the amount to take and when to be tested again. Seems a good system.

Best wishes, Liz

BobD profile image

About two years ago my medical centre told me I was no longer allowed to go to the hospital for my blood draw INR test as they had a coaguckeck machine. Since then I have the finger prick with instant results and dosage, not that it ever changes as I have been on the same dose for years. I am on 84 days interval.

For what it is worth Fi "accurate " is a term I wouldn't associate with INR testing as every lab will show a different results for the same specimen.. So long as you have your testing done at the same place each time then you should be O K whatever method they use. INR is such a complex and variable subject that as an engineer I was alarmed at the variations available but having discussed the subject at length with some really important people in the field I am assured that in range is in range and that one shouldn't get too precious about methods or numbers.

Hope your med centre gets a machine as it does save a huge amount of time. Anything else is just old fashioned!


PS I know of several people who bought their own machines and get the strips on NHS and if you are one of the unfortunate who's INR fluctuates a lot I think this is worth the cost for peace of mind.

MissL profile image
MissL in reply to BobD

Hi Bob I talked to my nurse about buying my own coag machine as my levels have never been consistent, she told me that I would have to buy my own strips as well as they are not available on the nhs? Did your surgery tell you that they would supply them ?

MarkS profile image
MarkS in reply to MissL


You shouldn't need to buy the strips, they should be available on the NHS. Mine are. They cost around £2 each is you buy them yourself but I'm sure the NHS with bulk buying can get that down to about £1 each. That's £50 p.a. which is one heck of a site cheaper than the cost of a stroke at £10's of thousands!

If they faff around with the computer saying they can't find them, quote Coaguchek XS Pt Test Strips 04625315.

If there is one thing that's going to cut the number of strokes, it's self testing (and preferably self management). I'd like to see the AFA setting up a campaign to ensure everyone gets these. They put together a campaign to get dronedarone approved by NICE, and that has subsequently been shown to not work properly. Coaguchek machines and strips have been shown to work. Getting them widely used would be a major step forward. How about it?


Beancounter profile image

Hi all

I'm obviously the unlucky one then, I go to the hospital, to the main blood test department for my INR testing, they take a smallish vial of blood and then the anti-coag nuirse rings me if she wants me to change my dosage, otherwise I get a letter about three days later (that would be first class in the UK I reckon :) ) I am on 6 weekly tests now.

I don't mind it to be honest you catch up with the same people often and have a chat, and the vampires are very good at their job, there are special sessions for those of us on warfarin.


G'day Feejbee,

For my reply read the same as Langara - at least when I lived in Surrey. I used and still use the Coaguchek device. When I go to Australia I take it with me and self monitor. However, since I've retired and moved to Cornwall my local practice draws blood, bottles it and sends it away. I have to wait 24 hours for the result. This surgery only does INR once a week on a Thursday. Most inconvenient and restrictive.

Previously, in Surrey my results came up on the Coaguchek device, the practice nurse entered the result into a computer into the coaguchek programme and the results were instant and in hardcopy.

Using the method my Cornish practice follows I have had one major mistake by the lab and/or surgery (not sure who is to blame) where I was given wrong results - identified by me I might add - so now I continue to use the Coaguchek method in tandem with the surgery method because I now don't trust the surgery. I find that when I use the second drop of blood from the finger prick method my results are constantly + or - 0.1 ............. so for me that is spot on and for me it is accurate. I am normally in the INR range of 2.4 to 2.6.

It means when I'm in Australia in November with my machine I now know with a high degree of certainty that if I get an INR with a result of say - 1.1 or 3.8 or whatever, I need to check a further check done.


Aussie John

BobD profile image
BobDVolunteer in reply to

John are NHS still supplying the strips? See Missi's post above.

dedeottie profile image
dedeottie in reply to BobD

Bob The NHS are supplying my strips but only enough for me to test my blood once a week so I would only need two prescriptions a year. Each prescription is for a tube of 24 strips. If I needed any more I would buy my own. I have found My Gp to be most amenable to this but the INR nurse is not! She thinks I should only test my blood as often as I would have in clinic which would be once every 8 weeks because my results show that I am stable. She doesn't get it that I am only stable because I keep an eye on my INR. I enjoy a varied diet and often my INR readings are high or low. When this is so I alter my diet slightly eg if its high I eat more green veg and if its low I eat less green veg. Anyway as long as my GP is happy to prescribe for me I am happy. To be honest I would buy them all myself if needs be for the peace of mind it gives me. I think everyone is different. Some people prefer to eat a similar amount of vit K each day and I guess that would mean a more stable INR. This way works for me. I should add that I now live in South Wales but previous GP in Lancashire also prescribed strips for me. Hope this helps

BobD profile image
BobDVolunteer in reply to dedeottie

I always assume that since my INR is OK when tested I must be stable but it is a good point that who knows what it is between testings (Mine at 84 days).

in reply to BobD

G'day Bob,

Hope you are well.

I believe they are but to be truthful since I have been in Cornwall I haven't had to ask for any. Just before I left Surrey I got a new batch but only test now just before I go for my INR 'blood letting' at surgery. At the moment I'm on 70 day tests and I do not use coaguchek to check my INR in between. I'm lucky in that I am 'INR stable' and always fall in the range 2.4 to 2.6. I have made very few concessions to Warfarin - no cranberry products at all - still eat green stuffs, still drink alcohol, but in lesser quantities, but, what I can't comment on is the impact of following a variation of the FODMAPS diet to address my AF. I just don't know how this diet affects my INR test results - obviously from these results not badly !! But - whatever I eat, I eat consistently.

When the time comes to ask for a repeat test strip prescription I'll approach my 'tame' GP (she did most of her training in Australia). Talking of that - when I'm in Sydney in November I'll price (as an over the counter purchase at non NHS prices) these test strips there and have a chat to someone about them

Just passed my annual PSV drivers medical for my PSV licence renewal - can't all be bad.


Aussie John

mine is usually finger done at coag clinic only time venous sample has been when my INR was above 8

I've only had the blood test once - when I was in Peterborough for a few days - the rest of the time one of my surgery nurses does the finger test whenever needed and it is extremely reliable. I am amazed that there are surgeries who do not have this facility.

Beancounter profile image
BeancounterVolunteer in reply to

I have to say wardways, I'm not sure if I trust my GP surgery to do it, so perhaps it's best I go to hospital.

After all these were the practice nurses that when they took my ECG, called a senior partner, and then another two partners, and then informed me I was having a heart attack, and how did I feel?

I said I felt fine, my BP and pulse were lowish, and what were they talking about, and they said they thought the ECG showed a heart attack.

Talking later to the Nurse Consultant in charge of the urgent chest pain clinic, she was only slightly astonished (her opinions of GPs and their knowledge of hearts being pretty dismal) and then asked why they hadn't called an ambulance if they thought I was having a heart attack.

I have to agree, so really not sure I want them doing anything as complicated as an INR check, think I'd prefer to do it myself.

Actually it somewhat terrifies me to think that these people are now in charge of commissioning local health services, I don't think they have a clue what their patients want, they never listen to us, we are simply numbers to get in and out the door as fast as possible.

Rant over :)


in reply to Beancounter

Hi Beancounter

I hear what you say and can fully understand how you feel. I'd feel the same I'm sure. However, I have every confidence in my surgery , both the doctors and the nurses. The thought of having to go to the hospital for a blood check each times really daunts me - half a day lost, severe parking problems and the consequent cost! And even then they can't tell you the result immediately. I'm on my third little yellow book now which I estimate is over a hundred coag checks. Perhaps I'm one of the lucky ones with a reliable and very helpful surgery.

It's good to be able to air our feelings in this way and I really do hope you have no more scary feelings

All the best



I have been having the finger prick INR Star test now for 3 years, the nurse at the surgery carries out the test. If you are prescribed antibiotics or other medication for a different problem then you will be asked to have the check more frequently i.e. once a week in case the new medication has increased or decreased your Warfarin level. I was apprehensive at first about going for a long time without my blood being tested, but I was assured by the nurse that if I was at all worried I could go and have it checked at any time.



Thanks for all your replies. Like Ian I'm one of the unlucky ones and have an "armful -to quote Tony Hancock" of blood taken .I have to go to the surgery on a Monday or Tuesday morning needing to take time off work and then ring for results 2 days later and like Aussie John I was on one occasion given the wrong result and the wrong dose of Warfarin to take .

I am thinking for flexibility and piece of mind I might buy myself a coaguchek machine or do I take one of the new anti-coag drugs At the moment I seem to be very settled with all the drugs I am taking including Warfarin, and amazingly, Bisoprolol - and as you all know that's a big thing, so not to keen to change and maybe upset the apple cart.

On a different note, up to the Royal Brompton next Thursday for 3 month check post ablation. The first 2 months were up and down although much better than before the ablation (thanks for all the advice that was perfectly normal ) but the last 3 weeks have been amazing and I feel almost back to normal .Hope I'm not speaking to soon but this is to me a miracle, amazing and wonderful .


Dadog profile image
Dadog in reply to feejbee

I don't think you are 'unlucky' in that respect, feejbee. I go to my local GP surgery for the 'armful' method, on a Thursday morning. It is sent away to the cardiac dept of the hospital where all this started; and the results are always in my letterbox on the following Saturday morning. For me, it is a simple and positive process and monitored by the experts in the hospital. Bit of a pest at first when the tests were fortnightly but now I am on a constant 2.5 and only need to go every 2 months.

Regarding self testing, it seems to be up to the various Trusts as to whether you would get the test strips on the NHS. They are very expensive. Glad things are going well for you.

I have the finger prick at my health centre and now only have to go every 3 (three ) months; unless of course a problem arises. Much more convenient !

At the moment I attend Warfarin Clinic for a fingerprick test every 5-6 days because I haven't been on the drug that long. I've been told that once the INR level has stabilised, I'll be able to have the check done at my GP surgery. As I live daily close to both, it isn't a major hassle!

Feejbe, what's the deal with Bisoprolol? I've just been put on it, together with Amiodarone and Warfarin.

feejbee profile image
feejbee in reply to Mamamarilyn

Hi Mamamarilyn

I found that with Bisoprolol I was so tired ,breathless ,dizzy etc. because my normal resting pulse rate had dropped from in the 60's to 45 -50 with low blood pressure as well 95/60 .Reading this forum many others seemed to report the same thing. I was taking 5mg daily but asked if I could take 2.5 twice instead .That seems to have made a big difference ,I still have the same readings as above but my body seems to have accepted that this is now normal and I'm not tired anymore and very rarely dizzy or breathless. Of course all this might be due to having had the ablation and not the drugs.


Hi Feejee

I have the fingerprick test and immediate results as well. At the moment, because I am preparing for ablation, it is every Tuesday at 8.50 and only 5 mins from home . Can't do much better than that.


Now that's really interesting because, having met a friend in town for coffee, I had no energy left to look around the shops with her (unheard of!) I was also a little breathless but not dizzy.

I'm wondering whether the drugs I'm on now cause word blindness too lol! I have no idea why I put the word "daily" in my last post!

I take my yellow booklet to the clinic, have a blood test the usual way, they keep the card and I usually receive the book back the following day with results. I think I prefer it that way, I have a record of all tests since I first started warfarin in the yellow book. It's good to have with me, each time I take my prescription in to the chemist, they always check the results and keep the details on their files. I keep the booklet wherever I go, it's there in case of accidents.

Dadog profile image
Dadog in reply to Vivante

I agree with you Vivante. I get a little blue paper with the results which my chemist also asks for every time I go for more Warfarin. I kinda feel looked after and cared for.

Bagrat profile image
Bagrat in reply to Dadog

I have coaguchek at surgery, instant result and print out for me also detailing last few tests and doses and date of next appt. They all sit in a yellow folder

I have the full 12 inch needle (at least that what it seems in my head I don't like needles) :( I have had a full test since 1992 when it plays well it is every 6 weeks but at the moment I am now every 2 weeks but not long ago every week. I have the scars on both arms to prove it.

Be Well


Enjoy profile image
Enjoy in reply to Offcut

How luck are you who can get it done at your local GP or Medical Centre. I have a 13 mile round trip to the hospital with petrol the price it is plus the time factor - I feel hard done by.

I have the "bottle of blood from the arm" method, approx every 2 weeks by a nurse at the my GP's surgery ( the blood is sent to the local hospital for analysis and telephoned to me usually on the same day

My INR result varies quite a bit ( possible due to my varied diet) and the drugs....Bisopolo, Mesalazine (for ulcerative colit) Flecainide and sometimes an antibiotic which definitely alters the INR reading, in my case..

DEDEOTTIE... you mentioned with respect to the consumption of greens that your INR reading goes higher if you decrease your intake of greens. Have you managed to confirm this from your meter readings.?

..I am a bit confused about the effect the consumption of greens has on my INR readings.

dedeottie profile image
dedeottie in reply to rosailor

Hi Rosailor. My monitor definitely confirms that more veg or fruit with vit K = lower INR. It usually takes a day for it to get into my system and register on the monitor. Because I don't want to restrict my intake of these fruit and veg I am on quite a high dose of warfarin ( as recommended by the hospital ) but then if I have a few unhealthy non veg eating days my INR will go up.Again this does register on my machine. Im sure others may have different experiences but this is how it is for me. It gives me confidence to know that my INR is completely in range all the time. However my husband would probably prefer not to know if it was him. We are all different. The down side of this is that If I drink more alcohol than I should it also registers a higher INR on the machine. I think I would prefer not to know that!

I have an ' armful ' taken at my local surgery 2 minutes away & the result is e mailed to me from the path lab later same day . No problem.


Dodie117 profile image
Dodie117 in reply to

I have arm method at coag clinic in hospital. I have a yellow book and results entered there. If I wait an extra 30/45 mins I get results immediately. Otherwise will post the book. I am now on 8 week intervals but I have coaguchek machine so do some more checks at home. fluctuate quite a lot and have to avoid the temptation to do tests every day. Nurse said if it ever goes to 4 ring him and he will adjust warfarin dose. On the day I have the hospital test I do one on my machine to check it is showing more or less the same result. All seems fine. This works well and I can go away for long periods and still feel secure. Marie

Hi; I have my checks done via the fingerprick method conducted by the coag clinic at the hospital ( long waiting times, parking charges etc ) I intend to purchase my own test machine, the test is simple and a lot less time spent hanging about. Only down sides are cost of machines are around £400-00 and my gp surgery will not fund the strips however, I will not require too many strips so it looks like a winner all round. hope this helps

Dodie117 profile image
Dodie117 in reply to beejay16813

Beejay. The machine is not that bad. Its £299. Also, my gp said no but then changed his mind as nice recommend - so keep trying!! Marie

beejay16813 profile image
beejay16813 in reply to Dodie117

Hi lallym; Thanks for taking the time to respond. I intend to keep trying to get gp to supply the strips. I would be interested to hear where I can obtain the machine at the price you mentioned. Thanks once again and stay well

Dodie117 profile image
Dodie117 in reply to beejay16813

The makers are Roche. Look at

I go to GP surgery where the blood nurse does the finger prick test , she shows my GP who authorises my dosage . I am having weekly checks at the moment as off to London 17th Sept for 4th ablation , it all seems to work well for me .

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