Coag-Sense versus CoaguChek xs and labs

[tom in MO]

actually its an entirely correct one, you have a metabolism which allows your INR to remain stable, I do not believe this is common across even most of the community. Yet you continually brag about how "My INR is super stable" ... that's not helpful to someone to whom its not. Someone new who has as yet not realised that INR variations are the NORM not the exception.

A quick look at almost EVERY study shows that most people are not stable without intervention. You claim that you do nothing to keep it within a range of far narrower band than almost anyone in the group. Further I'm willing to bet that I have more discussions with people about their INR than you, and what I see is that such a band of 0.5INR units is impossible for most most of the time without some adjustments. You frequently claim you make none.

Your continual posting in this reguard would be like The Gym Guy saying "I bench 200kg, its easy"

Genetic predispositions matter ... height is one and so are the many and various aspects of metabolism including INR.

sorry about getting " and ' mixed up ... I hate imperial anyway ... ;-)

Sorry your ananologies, personal experience and expertise is belied by what you ignored in my post:

At least two valve product lines, from two different firms, have had studies that have shown that narrower ranges (+/-0.5 INR) are safe, can be achieved and are thus recommended. This means there are many people that can maintain that narrower range. Those are consensus opinions maybe even actual facts. Probably conservative opinions/facts given the litigious nature of US society.​

Both my two cardios and former coumadin clinic do not say an 0.5 INR range is not attainable by the average Joe. They do say it requires testing and they recommend every 2-4 weeks but approve weekly testing for purposes of INR resupplies.

Those who post and contact you may not be "average" in that they have trouble maintaining an INR. Those who can maintain an INR would not be requesting the forum's or your advice since they do not need it.

 

[Protimenow]

I am always anxious the day I test. I can't help it. I have to switch to Jantoven in a month or so. I will be out of Coumadin. Doctor already gave me prescription for Jantoven. I am super anxious about the change. This blog helps me manage it. Thank you to all who help. He did say he wants me to test every week at first when I make the change. It will probably be end of October more or less. Ill post how it goes. Will I be able to eat the same way? Will I still be able to have my wine in the evening? I usually have one or two. Hope so. Best to everyone.

Jantoven didn't work for me -- I couldn't manage my INR. I had to take generic warfarin, instead of Jantoven (yes, there's a difference). You shouldn't have to make any changes to diet or activity - in fact, you shouldn't so that, if there is a change in INR, you'll be able to point at Jantoven as a possible cause, rather than your other changes.

I wouldn't stress over the change. (But you might ask about generic warfarin instead of Jantoven)

 

[Protimenow]

Wow. This thread has certainly strayed from the original intention - comparing CoaguCheck XS to Coag-Sense to lab results.

In a lot of tests a few months ago, after getting home from one of my hospitalizations where they reduced my INR, I monitored as I brought it up - using CoaguChek XS and Coag-Sense. At low INRs (sub-2.0, up to about 2.3 or 2.4, both meters recorded similar results). At higher levels, the two meters diverged quite a bit.

I ran out of strips for my XS, so I was only using Coag-Sense strips for a while. I assumed that, with values above 2.4 or 2.5, the XS results would be 'about' 1.0 higher.

I was fortunate to get some new XS strips. On Tuesday, the new strips arrived.

My Coag-Sense gave me a 2.7 - slightly high, if I added the 1 point difference that I expected from my XS. I was a bit surprised - and slightly troubled - when the XS gave me a 4.1. I have a standing lab order for INR, so I went and had a blood draw - I really didn't want to have an INR THAT high, but it wasn't that big a deal.

Years ago, when I did a LOT of testing so I can find a meter that I could trust with my life, when my INR was around 2.5 - 3.5 (or so), the XS result was slightly higher than the Coag-Sense result, and the labs were almost always the average of the two meters.

I just got a call from my HMO's anticoagulation clinic -- the lab result WAS the average of the CoaguChek XS and the Coag-Sense meters - 3.4. I just didn't like the range between the meters. I'm not happy that the Coag-Sense result was .7 lower than the lab, and the XS result was .7 higher.

My HMO won't authorize new strips, but they're happy paying Alere a lot more than it's worth to provide me with a new meter and strips. Maybe a new meter will make a difference?

(FWIW - the person at the coagulation clinic told me that a difference of .5 is okay)

 

[ATHENS1964]

Today the LAB give INR 2.6 and xs 3.0 what is your opinion for the difference 15% I should to set a goal 3+ with XS ?
The lab is the same every time and the difference is 45 minutes for two measuring .
I will be worried if I get a result of 2.6 with XS I will have to increase the dose of the drug;

 

[dick0236]

Today the LAB give INR 2.6 and xs 3.0 what is your opinion for the difference 15% I should to set a goal 3+ with XS ?
The lab is the same every time and the difference is 45 minutes for two measuring .
I will be worried if I get a result of 2.6 with XS I will have to increase the dose of the drug;

My experience is I seldom have had Lab and Selftest agree. The .4 difference is not enough to worry about unless such a difference continued between several tests. I assume your range is 2.5-3.5 and I would never change a dose if I was anywhere in that range.......or even if I am within +/- .3 of my range on a single test. Take a breath and relax a little, this is not rocket science.

 

[MdaPA]

The insert that comes with my wife's CoaguChek XS PT test strips says:

Differences in reagents, instruments, and pre-analytical variables can affect prothrombin time results. These factors should be considered when comparing different prothrombin time test methods. Experience comparing results obtained using the CoaguChek XS System to those obtained using common clinical laboratory reagents shows that the CoaguChek XS System correlates well with the following clinical laboratory reagent: Dade Innovin. Other clinical laboratory reagents may not consistently correlate with the CoaguChek XS System.

As I posted earlier in this thread, when I called Coaguchek Patient Services, the representative said a 20% deviation from the lab or even against another machine was the upper limit due to the factors listed above. I think we should be concerned when the XS to lab deviations start becoming inconsistent (and not from just one test) or become > 20%.

My wife is getting fairly consistent higher results (between +.3 to +.5) from her XS when compared to the lab. Her latest comparison came today (XS = 3.1, lab = 2.7). So I think we can say her INR falls somewhere within the range of these 2 results and make any dosage adjustments based on the trend from that. We no longer expect them to match or try to guess which result is correct.

 

[Protimenow]

I wouldn't make adjustments to dosage based on the differences -- in either case, you (or your wife) are in range.

I'm dealing with a different situation:

I reported that my Coag-Sense gave me a 2.7, my XS a few minutes later gave me a 4.1. The lab, two hours later, gave a 3.4. This brings up the 'which do you trust'? question.

I made a small reduction in my dose the day of the testing - dropped from 6.75 to 6.25.

Yesterday at urgent care (don't ask), they did a test on THEIR XS. The result was 4.1 (the same that it was on my meter two days earlier).

I'm inclined to believe the XS - little cuts bleed a lot more than they should with a 2.7 or 3.4.

Last night, I skipped a dose, and I'm thinking of dropping to 6 mg (from 6.26 - I don't want to make changes too quickly. Of course, this missed dose will affect test results in a few days. I'll drop my dose to 6 tonight.

Next week I'll check with both meters and see if my INR has dropped back into range.

I'm quite concerned about the consistently low results of the Coag-Sense meter. This was the original reason that I started this thread -- to find what users of the Coag-Sense are experiencing when comparing their machine-generated INR values to lab values (and, possibly, to XS values).

I'm concerned that others may have similar lower-than-actual values and may be overmedicating as a result. If this is only the case for me, I'm wondering WHY this should be so.

Thanks for reading one more of my long posts.

 

[Sheenas7]

Jantoven didn't work for me -- I couldn't manage my INR. I had to take generic warfarin, instead of Jantoven (yes, there's a difference). You shouldn't have to make any changes to diet or activity - in fact, you shouldn't so that, if there is a change in INR, you'll be able to point at Jantoven as a possible cause, rather than your other changes.

I wouldn't stress over the change. (But you might ask about generic warfarin instead of Jantoven)

I asked cardiologist but he told me he wanted me to try Jantoven. He says it’s more like my Coumadin. I just picked up my first prescription. I still have about 3 weeks of Coumadin left...
I also take a baby aspirin.

 

[MdaPA]

I wouldn't make adjustments to dosage based on the differences -- in either case, you (or your wife) are in range.

Yes, no adjustment to my wife's dosage based on todays results (XS = 3.1, lab = 2.7) as her INR is in range (2.5 - 3.5). If XS came in at < 2.8, then that's when we think to change the dosage to up her INR (as if she went to the lab, our experience is that the lab would have come in around 2.3 - 2.5 (as XS is usually +.3 to .5 higher).

 

[MdaPA]

I reported that my Coag-Sense gave me a 2.7, my XS a few minutes later gave me a 4.1. The lab, two hours later, gave a 3.4. This brings up the 'which do you trust'? question.

Protimenow,
Seems reason for concern for sure. How about submitting your findings to the FDA?

All health care providers, patients and caregivers, are strongly encouraged to voluntarily report INR test meter problems directly to the FDA through MedWatch, the FDA’s voluntary reporting program.

Reporting a problem to FDA with Warfarin INR Test Meters

 

[Protimenow]

I tried to report an issue a few months ago, and got no response.

I will probably try again - thanks for the link.

 

[ATHENS1964]

Yes, no adjustment to my wife's dosage based on todays results (XS = 3.1, lab = 2.7) as her INR is in range (2.5 - 3.5). If XS came in at < 2.8, then that's when we think to change the dosage to up her INR (as if she went to the lab, our experience is that the lab would have come in around 2.3 - 2.5 (as XS is usually +.3 to .5 higher).

I had similar results 2.6 lab 3.0 XS it seems that there is a difference of 15%. when the movies are over and I get new ones I will check again in LAB to see if there is a difference of 15% again or it has to do with the movies and the chip.

 

[Protimenow]

Things keep getting, as Alice would say, curiouser and curiouser.

Last Friday I had a blood draw and, of course, tested with my meters:

Coag-Sense 2.0
CoaguChek XS - 2.5 (a bit of a surprise, I expected the XS to be closer to 3.0)
Lab - 2.8

I realize that the XS and lab were within 20%, and if you figure 20% for the XS, the Coag-Sense is also within the margin of error. But there's no way to put the lab and Coag-Sense within 20% of each other.

I continue to be somewhat baffled by the variations.

 

[Sheenas7]

There was a FDA alert of test strips that were not supposed to sell in USA.
Here is a long explanation. Look for the company selling them.
Hopefully it doesn’t apply to anybody here. It may be old news. Not the first alert either.
https://www.drugs.com/fda-alerts/2311-2631.html

 

[ScribeWithALancet]

There was a FDA alert of test strips that were not supposed to sell in USA.
Here is a long explanation. Look for the company selling them.
Hopefully it doesn’t apply to anybody here. It may be old news. Not the first alert either.
https://www.drugs.com/fda-alerts/2311-2631.html

Sheenas7,

Thank you. Happily, my CoagSense was not affected. I normally check my CoagSense against my health plan lab every two to three months. So far, they have correlated well. However, my strips have come from only two batches and the Lab has not changed machines or Thromboplastin.

Walk in His Peace,
Scribe With A Lancet

 

[Protimenow]

I'm pretty sure that the test CoaguChek test strips that were recalled have, by now, expired. I know that there were some sellers on eBay that sold the recalled strips - some of them had the theory that, once a person bought them, all that they had to do was call Roche and Roche would replace them.

I'm not sure that this happened - the customer may have had to contact the dealer who sold them (not the guy on eBay that sold them) and ask for replacements.

But, by now, I think that most, if not all, have either been replaced or have expired.

The recall had NOTHING to do with Coag-Sense.

I'm getting some CoaguChek strips (thanks to the now anonymous friend who is sending them to me) without a chip (I have a few, but will probably use the most recent chip) to see how closely the results are to each other. As usual, I'll compare the results to my Coag-Sense and a lab.

If what's happening with my Coag-Sense results (significantly lower than lab or XS) is happening to others, I WILL have to go to the FDA.

 

[ATHENS1964]

interesting study for testing in laboratories.
https://www.degruyter.com/view/journals/cclm/56/10/article-p1698.xml?language=en

 

[Protimenow]

Yes. Interesting.

 

[tom in MO]

interesting study for testing in laboratories.
https://www.degruyter.com/view/journals/cclm/56/10/article-p1698.xml?language=en

Thanks for finding this and providing the link. Since the lab results are a "black box" to me (e.g. I don't know what method they use and what calibration they do), what I got out of the results was

• Clinically significant differences in INR results (difference in INR>0.5) were observed between different reagents. To me this means don't worry unless an INR differs >0.5, but it may be the lab not the meter.
• No systematic significant differences in the between-laboratory variation for a single-plasma sample and a pooled plasma sample were observed. For any single blood sample there was no significant differences between laboratories

Not much we as the patient can do as far as the only "Conclusion": The comparability for laboratories using local calibration of their thromboplastin reagent is better than for laboratories not performing local calibration. Implementing local calibration is strongly recommended for the measurement of INR.

 

[Protimenow]

I'm not sure if I should start a new thread, or just continue with the current one.

For the past four tests, I've used the CoaguChek XS (and not the Coag-Sense). Although testing with the Coag-Sense didn't add much hassle to checking my INR, the CoaguChek XS is still considerably easier.

I will probably have a blood draw in a few days, and will use both meters to compare to the lab results.

The XS, in the past, was usually closer to the Lab than the Coag-Sense (although the last blood draw was closer to the Coag-Sense). As long as my INR is in range, I'll probably continue to use the XS, as long as my supply of strips holds out.

The Coag-Sense is still a good meter, and probably performs very accurately for most users. There seemed to be something about my blood that seemed to confuse the meter - results were more than 20% different from the lab, and, for INR above around 3, the difference from the XS was also higher than I would like for it to be.