Different results?? What do you think??

[aussiemember]

Hi everyone,

Had a MVR back in March - have been home testing with an InRatio machine and have had no problems - I get my INR tested at a lab once a month as a back up to the machine and so far the results have been very similiar.

My problem is this: I test once a week at home and tonight I got a reading of 6.2!! I was suspicious of this as there seemed no reason behind it so I tested again straight away. This time I got a reading of 4.8!! The only difference between the tests was a different finger and a new box of strips. (Just coincidence I was up to a new box). Since both tests are over I am reducing my dosage for the next couple of days - and will go to the lab on Friday to get a test there as a back up. Has anyone had this happen to them? It makes me wary of home testing now with such a big difference on the two tests....

 

[bvdr]

I can't explain the difference but I know it happens....even in labs. They both show you high so you are better off than if you were low. I read in some article that the higher your INR is the more variance you can get in testing. In other words, they are more accurate in the lower ranges.

Does anyone else remember reading this?

 

[catwoman]

Where did you purchase the strips from? I assume the strip for the 2nd strip came from the newly opened box.

Because your lab test won't be until Friday, it will be hard to compare the 6.2 & 4.8 against a lab test several days later. How long does it take to get INR results from the lab test? Is it a finger-stick test or a lab draw?

If it's a draw and you have to wait for results, it's a little difficult to compare results. Probably best to run a test on your INRatio immediately before having the lab test.

I'll be interested in what others here have to say.

 

[AgilityDog]

The higher you are, then the less accurate the number on the tests. Both numbers warrant a reduction in dosage, and/or a hold of a dose, and a re-check 3-4 days later if you need it for comfort, otherwise in a week.

I was 5.4 on Sunday, after being in range and on the same dosage for 6 weeks. Not enough veggies or exercise last week, I suppose. I had a seminar for 2 days with bad food choices, and stuck in a chair for hour upon hour. So this week I'm making sure I exercise and eat some spinach.

It happens. I tend to fluctuate a lot with exercise and water retention problems. I adjust. I don't change my lifestyle unless I hit a 6, then I might skip an activity with higher risk of injury for a couple of days.

 

[dick0236]

The higher you are, then the less accurate the number on the tests. Both numbers warrant a reduction in dosage, and/or a hold of a dose, and a re-check 3-4 days later if you need it for comfort, otherwise in a week.

.

I had an INRatio machine a couple years ago. The above comment is exactly what the manufacturer of that machine told me...."the higher my INR, the less accurate the machine was and readings that high only reflected that my INR was out of range on the high side". I would reduce my dosage for a day or two and retest in a week.

 

[olefin]

I would say your INR is out of control!
I once didn't believe my INRatio2 meter, it happen not too long after I started home testing.

I tested 6.2, rechecked another finger on other hand 7.1. It was after hours. Called QAS, they first suggested switching to a new box of test strips. I did and retested, 5.9. Then suggested testing my wife if she didn't mind. I tested her, 1.1. (she's not on warfarin) So I stopped warfarin and called my cardiologist the next morning. He wanted me to hold warfarin for 2 more days and retest on forth day. I didn't follow his instructions, I skipped taking one more day and tested 2.1. Started back at 5% reduced dosage. Was in control on next test.

I've read that the accuracy of the meters fall considerably when over control range.

For the first couple months I was having to go in for lab test once a month. On my regular checkup with my cardiologist I discussed going to full home testing and dosing. He said if I got into a problem to let him know and that was it. My last lab test 8 months ago.

 

[EVELYN]

Why don't you test someone who is not on ACT and see if he/she is in range with the machine. That way you'll know if the machine is correct/within range. You did remember to change the code on the INRatio when you changed strips, yes?

Evelyn

 

[aussiemember]

Hi everyone,

Thanks so much for your feedback. It is interesting to hear that once you are high then there can be variance in the tests. The only reason I can think of that I am too high is that I am on a diet so have reduced food consumption, increased exercise and am losing weight. I will adjust my dose accordingly from now on.

I purchased the strips from the same supplier in Australia who distributes the InRatio machine so I am fairly sure they are reliable. I did remember to change the number to match the new strips. I will retest tomorrow (Friday here) and I can get the lab results on the same day so will ring and get the results. Will let you know what they are

PS: Good idea about testing someone else - Next time I'll get my husband to be a guinea pig!!

 

[catwoman]

The only reason I can think of that I am too high is that I am on a diet so have reduced food consumption, increased exercise and am losing weight. I will adjust my dose accordingly from now on.

You've probably hit the nail on the head.
Even though you've increased your exercise, you have no doubt gone to a low-fat diet. Fats contain vitamin K.

When I started on Weight Watchers in June 2004, my INR went up. After doing some research, I determined it was because my vitamin K intake had gone down with the low-fat diet.

This is why warfarin patients are cautioned about changing eating habits. It's OK to do so, but you need to be aware that your warfarin dosage will need adjustments.

 

[Cris N]

In addition to the other comments just wanted to ask... did you make sure the code was in the machine correctly for the new strip?

 

[aussiemember]

In addition to the other comments just wanted to ask... did you make sure the code was in the machine correctly for the new strip?

Thanks Cris, I'm pretty sure I did but will check it next time

 

[aussiemember]

You've probably hit the nail on the head.
Even though you've increased your exercise, you have no doubt gone to a low-fat diet. Fats contain vitamin K.

.

Wow!! That is really interesting and would totally explain the increase - thanks for your answer

 

[Freddie]

Didn't know about the fats containing fats - good thing to know.
But have you checked your battery in your machine? Just a thought.

 

[AgilityDog]

Vegetable oils contain vitamin K. Lard (hamburger type fat, bacon grease) would have less.

Plus, if you lose weight, your dosage will change. Mine does with just a 5 pound fluctuation.

 

[catwoman]

Vegetable oils contain vitamin K. Lard (hamburger type fat, bacon grease) would have less.

Plus, if you lose weight, your dosage will change. Mine does with just a 5 pound fluctuation.

I've seen posts indicating that if you leave oils out (exposed to sunlight) for X days that it will decrease the amount of vitamin K. HOWEVER, oils exposed to sunlight also become rancid more quickly.

I have just adjusted my dosage, rather than leaving oils in sunlight.

 

[Ross]

Dose adjusting is so much easier then trying to diet the dose.

 

[aussiemember]

I thought I should update this thread for those who were kind enough to give me feedback.

I retested last Friday and got a 4.2 which was consistent with my dosage correction and the INR being on the way down. I didn't want to go to the lab with this as they would have gone into panic mode so I tested my husband for reassurance and got a perfect 1.0 for him!!

I then retested Monday and got 3.4, went to the lab and their result came through from pathology that evening - 3.2!! So I am reassured about the accuracy of my meter.

As to the discrepancy in my original testing - I am going to go with the theory that the higher the reading the greater the variance in accuracy with the home meters. This does make sense and at the end of the day as long as I adjust my dosage down and retest in 3 days it doesn't really matter.

Thanks so much for those that replied

PS: You should have heard my husband whinge about how much the finger prick test hurt - I told him try having open heart surgery!!!

 

[Ross]

PS: You should have heard my husband whinge about how much the finger prick test hurt - I told him try having open heart surgery!!!

Next time, zap his toe when he's sleeping.