Coag-Chek meter information wanted

[Jamey T]

Since the Inratio 2 has been discontinued, and I really dislike my Coagucheck XS due to reading very high compared to blood draws, I am considering this meter. Is there anything "special" that needs to be done with this meter? ProtimeNow, I am considering this based on your reviews and I would appreciate your input.

I can always just buy strips for my Coagucheck XS, but it has always read about .6 high compared to a blood draw at my local clinic. It was consistent enough where I would tell the ladies doing the blood draw what it would be based on my finger stick test, and I was usually within .2 of my guesstimate. I have kept record of every INR test I have had since my valve job over 5 years ago, so I do have a history I can look back on. My Inratio 2 is usually .1 lower than a blood draw, but now back to the subject.

I have a health plan at work where I put money aside for health expenses, and I need to spend some of it or lose it. My wife said if I wanted a different meter to get it, even though it seems to be a waste to spend the extra money when I have a Coagucheck XS.

Does anyone have any input on this meter? I will be buying on eBay, as my health insurance company says I live close enough to the clinic to not need a meter.

Thanks!

 

[dick0236]

Before I spent a lot of money I'd check the CoagXS by sticking my wife, or a friend, who is not on AC. If the reading is around 1.0 the meter is OK. If you get a +/- 1.6 (.6 high) then the meter is bad and I would contact Roche Diag.......maybe they will replace it as I'm sure they would not want defective meters being used........that's what got INRatio in trouble. BTW, never assume the lab is always correct.

 

[LondonAndy]

Before I spent a lot of money I'd check the CoagXS by sticking my wife, or a friend, who is not on AC. If the reading is around 1.0 the meter is OK. If you get a +/- 1.6 (.6 high) then the meter is bad and I would contact Roche Diag.......maybe they will replace it as I'm sure they would not want defective meters being used........that's what got INRatio in trouble. BTW, never assume the lab is always correct.

I agree with Dick0236 - here in the UK our National Institute of Clinical Excellence (which recommends best practice for the NHS in England) only recommends the CoaguChek XS. There are more potential variables with a lab test than with a meter.

 

[Jamey T]

The problem with doing a test is I would have to buy test strips. That being said, I should have tested my wife, and now wish I would have.
I have gone through two orders of 48 strips with that meter, and it has been consistently off by that amount. I doubt that Roche would do anything since I bought it on eBay, as I have all my supplies for the last five years. Yes, I did all the things that were needed to be done with the chips etc. and I am very consistent with my testing. I have had my Inratio off consistently by a small amount also, but it has always been closer to the lab than the Coagucheck.
If I saw large swings on the results between my test and the lab, I would double check the lab, by doing two lab tests in the same day at a different lab, but the results have been very consistent with the variances in my meters for the last five years. My lab does the testing in house, and I almost always have my results in under two hours.
One other thing to mention is that I am truly self testing and self regulating my doseage. I have talked to my doctor about this, and while he isn't a fan of it, he accepts it. I don't use a "service" or other outsider to report my results to.
If I don't get enough of a reason to buy another new meter, I will be buying another lot of strips for the Coagucheck XS. I don't have a big problem with the results being off, as long as they are consistent, and they have been. I have just gotten spoiled with my Inratio 2 being .1 under the lab with this lot of strips. My spreadsheet sure looks a lot nicer for the last year!

I appreciate the comments, and I am going to hold out for some input on the other meter before I do anything.

 

[lance]

Started home testing in 2004 first using Coaguchek S and then thecCoaguchek XS when it first came on the market. Spouse has been using it as well for the past 5 years. We're both totally satisfied with the performance and accuracy. I can't comment on other manufacturers but believe their users wouldn't go without Point of Care home monitoring either.

 

[pellicle]

...
I appreciate the comments, and I am going to hold out for some input on the other meter before I do anything.

sorry, intended to answer this last week, somehow got distracted and it slid off the radar.

I'm a little confused becaus I'm unclear if you do or don't like or are or aren't talking about the Coagucheck XS ... In my view Its a good meter (I use it) and my own experience with it is that its very close to lab processed vein draws. Normally 0.2 different

All the tests (both independent and submited by Roche in the process of testing for certification show that the meter is reliable, consistent and accurate. I can send you some PDF's if you like:

Firstly its important to know that NO INR TESTING IS PERFECT ... its not like picking up a piece of steel and measuring it with a caliper. There are multiple chemical (called reagents) involved. For instance:

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So some test results against some commercial machines (like an i-Stat which is often used in hospitals to actually read the blood they took from your vein draw.

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Myself I normally take myself along to a lab about once a year to get a draw done and then test immediately that I get home to then compare the results (when the lab results come in days later)


I would wonder if the "differences" you've seen in the past are down to the lab not the meter. Could you clarify what differences you've seen and in which directions?

Nothing special needs to be done with the XS to get readings, but under some circumstances (IE some blood disorders) you can get weird results. Are you following the guidelines in the manual for testing?

If you have any other questions please ask

 

[Freddie]

Were did you keep the Coagucheck XS test strips, in the fridge? Has the unit itself been kept at room temp?

 

[Jamey T]

Were did you keep the Coagucheck XS test strips, in the fridge? Has the unit itself been kept at room temp?

No the strips were not kept in the fridge. The instructions do not recommended that.

I meant to ask about the Coag-Sense meter, but I can't edit the title anymore.

I have been self testing for 5 years, so I am not new to it. For me the Inratio has been closer to lab tests than the Coach check. After reading pellicles post, I now need to ask the clinic how they do the tests. One other thing is, this is not a "Coumadin clinic", it is a regular medical clinic attached to the hospital, so I don't have any horror stories like some here have had.

It really isn't that big of a deal, and maybe the next set of 48 strips will be closer

I want to thank everyone for their input, I think I am going back to the Coaguchek XS, and making sure my INR is high enough.
.

 

[pellicle]

Hi

... After reading pellicles post, I now need to ask the clinic how they do the tests. One other thing is, this is not a "Coumadin clinic", it is a regular medical clinic attached to the hospital, so I don't have any horror stories like some here have had.
.

love to hear what they say ... I'm totally sure they won't have the faintest idea and will say "we send it to a lab" (meaning don't ask more questions than that). I'd also be interested if they follow the proper storage and handling protocols too.

My advice is this:
"Confucius say: scientist with one thermometer know temperature, scientist with two has uncertainty"

 

[Jamey T]

Hi



love to hear what they say ... I'm totally sure they won't have the faintest idea and will say "we send it to a lab" (meaning don't ask more questions than that). I'd also be interested if they follow the proper storage and handling protocols too.

My advice is this:
"Confucius say: scientist with one thermometer know temperature, scientist with two has uncertainty"

I know they do it on site, I had already asked that.

I went ahead and ordered the Coaguchek strips.

 

[DachsieMom]

About twice a year, I test my Coagucheck after a blood draw. This time, I did it about two hours later (and after eating). It was 2.2, the lab was 2.0 (my range is 2.3-2.8). About 6 months ago it was .1 higher than the lab, and before this out .2 higher than the lab.

 

[Protimenow]

I'm sorry that I didn't see this until now, My experience with the Coaguchek XS has been a bit unreliable. Sometimes it's close to the lab, other times it's way high. It's usually within the 30% margin of error that is acceptable. The issue that I had with the Coaguchek XS is that it almost invariably gives me a value that is higher than the lab value. What concerns me is the occasion where the XS gives me a 2.0 or 2.1 -- does this mean that the lab will actually be 1.7 or 1.8? Do I have to adjust my warfarin dosage? This is not crucial to my health, but I'd prefer to use a meter that is UNDER the lab results, rather than ABOVE the lab results.

As far as the Coag-Sense is concerned, it uses a method for determining INR that is similar to the one that some labs use (tilt-table), running a physical test, rather than an electronic test. I was told that for INRs above 4.0, some clinics have actually used the Coag-Sense to verify the values before they send the blood to a lab for testing. I think that, overall, the Coag-Sense more accurately reports INR.

That said, I know that Roche owns the INR testing market. The meters are more easily found, the strips are easy to locate. In most cases, the accuracy of the meter is 'close enough.'

As was also said, not all labs can produce accurate results. I've had some comparison testing where I've had blood draws at two locations, and tested with the Coaguchek XS and the Coag-Sense. The results of the labs, in some cases, varied by as much as one full point (not a tenth - a full point). This suggests that one facility may have improperly handled the blood before sending it to a lab for testing.

The Coag-Sense IS Clia waived, and probably can also be purchased by insurance or Medicare (if you're in the U.S.). It's the meter that I trust with my life (and I still get occasional blood draws just to be certain).

If you want more information about my Coag-Sense, send me a private email. I'll work on getting back to this forum sooner (and I think that I get an email that I've gotten a message, so I'll know to respond to you. Also - I have a spare, if you're interested)

Jamey T - you said that you have enough supplies for five years - I hope you just meant lancets - your strips will certainly expire before that.

 

[Jamey T]

I'm sorry that I didn't see this until now, My experience with the Coaguchek XS has been a bit unreliable. Sometimes it's close to the lab, other times it's way high. It's usually within the 30% margin of error that is acceptable. The issue that I had with the Coaguchek XS is that it almost invariably gives me a value that is higher than the lab value. What concerns me is the occasion where the XS gives me a 2.0 or 2.1 -- does this mean that the lab will actually be 1.7 or 1.8? Do I have to adjust my warfarin dosage? This is not crucial to my health, but I'd prefer to use a meter that is UNDER the lab results, rather than ABOVE the lab results.

As far as the Coag-Sense is concerned, it uses a method for determining INR that is similar to the one that some labs use (tilt-table), running a physical test, rather than an electronic test. I was told that for INRs above 4.0, some clinics have actually used the Coag-Sense to verify the values before they send the blood to a lab for testing. I think that, overall, the Coag-Sense more accurately reports INR.

That said, I know that Roche owns the INR testing market. The meters are more easily found, the strips are easy to locate. In most cases, the accuracy of the meter is 'close enough.'

As was also said, not all labs can produce accurate results. I've had some comparison testing where I've had blood draws at two locations, and tested with the Coaguchek XS and the Coag-Sense. The results of the labs, in some cases, varied by as much as one full point (not a tenth - a full point). This suggests that one facility may have improperly handled the blood before sending it to a lab for testing.

The Coag-Sense IS Clia waived, and probably can also be purchased by insurance or Medicare (if you're in the U.S.). It's the meter that I trust with my life (and I still get occasional blood draws just to be certain).

If you want more information about my Coag-Sense, send me a private email. I'll work on getting back to this forum sooner (and I think that I get an email that I've gotten a message, so I'll know to respond to you. Also - I have a spare, if you're interested)

Jamey T - you said that you have enough supplies for five years - I hope you just meant lancets - your strips will certainly expire before that.

No, I have a record of every test I have had taken for the last 5 years, since I had my valve replaced. I did get more strips for the Coaguchek XS, but it has been consistently much higher than my Inratio 2 or lab draws. But, thanks for the reminder, I am low on lancets.

Like you, I buy my own supplies, since our wonderful insurance said I did not need to self test since I live close to a clinic. Never mind that we travel as much as possible, but that is another discussion.

I have noticed that the lower my INR the closer the Coagucheck XS is, but when I over 3.0, the error is greater.

Thanks for all the responses, I know I rely more on this site than I post, but I still check regularly.

 

[Protimenow]

I've also noticed, when I used the Coaguchek XS and InRatio that there was more variance between blood draws and meter results when the INR climbed above about 3.2 or so. In fact, I think that some of this may have been documented. My Coag-Sense is usually about .1 or .2 below the lab that I use and I'm comfortable with that.

The insurance company doesn't take into account the hassle of driving to the lab, parking, etc., does it? It doesn't care that it's probably paying a lab quite a bit more than it ocsts to self-test.

Does your insurance pay for weekly testing? A test every month (or every two months) puts you at serious risk.

It sounds like you've probably got the right plan - test at home or while traveling. Go to the lab monthly to compare your lab's results to your meter's results. (I have an extra Coag-Sense meter, if anyone's interested)

 

[lance]

Does the insurance company take into account the wear and tear on your veins? Probably not. And the damage is cumulative.

 

[Jamey T]

I do a lab test about monthly with a draw, but I stick myself every week. I have noticed that the higher my INR, the farther off the Coaguchek XS is. As long is it is consistent I am ok with the error. I can adjust for that, and I just want to know that I am very low or excessively high. Luckily, I am very consistent and have only had to adjust my dosage a few times in five years.

 

[pellicle]

.... I have noticed that the higher my INR, the farther off the Coaguchek XS

This study on the device would seem to support that finding.

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I suppose in the "design tradeoff" phase they (Roche) may have been more willing to accept that given that being out more at higher INR is of less clinical significance than at lower INR (especially if you take a Log view of the signiicnce of higher INR)

Let me know if you want the PDF of the study

 

[Protimenow]

A few years ago, when I was more actively researching the correlation between meter results and lab results, I ran across some papers that also stated that both InRatio and Coaguchek XS had a higher variance from the lab values when the INRs were high. In my testing, when I tried to determine the most accurate meter for my personal testing, I also encountered this. The higher my INR got, the higher the error in results on these meters.

Because the variance increased in value, it wasn't possible to accurately predict the lab values - for example, if the lab and meter matched at 2.2, you'd expect a match at 3.5 - but with a meter, the 3.5 lab value may be read as 4.0 by the meter (I'm making up numbers here). And a 3.0 by blood draw may show up as 3.3. Clearly, it wasn't just a matter of subtracting an equal number from any meter's result in order to determine lab values.

A few years ago, one of the people on this forum calculated an algorithm to predict, based on the meter's results, what the lab results would be. I don't have that formula, but suffice it to say that if a mathematical formula is required to figure out what a blood draw would determine, the meters would be difficult for most people to easily use to predict their 'actual' INRs.

Of course - it's good to know the meter, and to be confident that, at a certain INR reported by the meter, the actual blood draw would repeatedly and reliably report a particular value. (For example, if the meter says 4.0, it would be good to KNOW that the lab would almost always say 3.5). This is kind of like a speedometer with a known error - if it says 20, you're going 20, if it says 70, you're doing 65 - KNOWING this makes the errors almost acceptable.

With that said - you really have to KNOW the actual value that relates to a value reported by the meter - and for many of us, this makes these meters somewhat less acceptable.

One thing that should be pointed out is that not all labs could necessarily be trusted to report accurately, either. I've had some INR results from labs that I chose to only use ONCE that were far different from the meter (and, occasionally, other labs that I used within hours of the erroneous lab). Not all labs can be always trusted to give good values.

FWIW - this error is one of the reasons that I chose to use the Coag-Sense. The Coag-Sense actually does a physical test for clotting - it doesn't use an electronic effect to determine when a clot forms. A meter that does an actual physical test, detecting a physical clot, doesn't rely on the same kind of decision making in designing the meter (can we make errors at the high end of the scale? as hypothesized by Pellicle) because there's no electronic phenomenon to be concerned with. In the case of my Coag-Sense meters, the correlation between meter and lab has been well within limits.
My meter often reports values that are slightly lower than those of the lab - and often give the same prothrombin times as the lab. This suggests that the values of the reagent for lab or meter are slightly different.

Personally, I prefer a meter that gives me a slightly lower number than the labs than I would to have a meter that reports slightly higher than the lab. With a meter that gives me a 2.0, I'd much rather assume that the lab value is closer to 2.2 than I would to have a meter tell me 2.0 and worry how much lower the lab value ACTUALLY is.

 

[lance]

Early on when I routinely performed comparison tests my XS and the lab agreed more than once. Usually there was a .1 to .2 difference--not enough to be concerned about and I don't remember whether higher or lower. The instruction booklet that came from Roche advised anything up to and including a .8 difference was accurate. Once when it took the lab 3 days to respond the comparison was .8 difference. At that point I considered comparison testing a waste of time the 3 days time frame being useless. Just my experience and feeling.

 

[Protimenow]

I can't imagine a .8 difference being acceptable in all cases. If a test result was 2.3, does this mean that an actual INR of 1.5 is acceptable? I believe that the acceptable standard is +/- 30%. This is what most meters can do - in my experience CoaguChek XS had a higher degree of variance at high INRs - and I believe this has been well documented.

When I got my InRatio, I trusted it completely - and paid the price. When I compared it a few times to lab draws, I contacted Alere and was asked which to believe - their answer was always 'trust the lab.'

For my own testing, I use the Coag-Sense. It has always been very close to MOST labs. I say MOST labs, because some labs don't seem to get an accurate result. I've verified this by having blood draws at two different labs, plus testing with my meter, all within a few hours of each test.

I'm now trusting my Coag-Sense meter, and doing a blood draw to confirm continued accuracy, every few months.

If you keep records of your INR results - both meter and lab - it shouldn't matter too much how long it takes for the lab to give you results, once you develop a validated trust in your meter. For me, I record the results of both lab and meter. The last time I compared the two, the INR was the same, and the prothrombin times were within .4 seconds of each other.

If you aren't already doing so, keep a record of your test results, your warfarin dosages, and anything else that you think may have affected your INR. If you get your blood draw the same day as your self-test, you'll be able to plug lab values into the record - whenever you get the results - and be able to make the comparison.