a brief INR management example (from my life)

[pellicle]

Hi

my dose has been 7.25mg for the last few months, but recently something changed and my INR went high. So here is my steps and methods in working through handling this and determining my new dose:

http://cjeastwd.blogspot.com/2015/10...r-example.html

best wishes

 

[dreamwarrior13]

Great post I was wondering, how often (if ever) do you go to a clinic or lab to get your INR checked or your dose managed?

My clinic just decided to scrap the home monitoring protocol they've been working on because too many patients they tried it out on failed to comply with the basic guidelines. So at MOST I'll be able to go four weeks at a time without having to visit the clinic. And that's assuming my INR starts to behave itself properly soon. Sigh.

(On the bright side, my last check was actually perfectly back in range, thank goodness.)

 

[pellicle]

Hi

Great post I was wondering, how often (if ever) do you go to a clinic or lab to get your INR checked or your dose managed?

I go to my Dr every 6 months or a year to get him to request a blood test which contains triglicerides and INR. I get the blood draw done and take my fingerstick measurement less than 20 min apart. So I then keep track of how well I'm doing with the clinic. It has not been greater than 0.2 different for a few years now.

My clinic just decided to scrap the home monitoring protocol they've been working on because too many patients they tried it out on failed to comply with the basic guidelines. So at MOST I'll be able to go four weeks at a time without having to visit the clinic. And that's assuming my INR starts to behave itself properly soon. Sigh.

(On the bright side, my last check was actually perfectly back in range, thank goodness.)

sounds annoying (the clinic I mean) .. don't worry about your INR being up and down, as you saw in my post my INR varies all round the shop but (important point) remains within range without adjustment. One of the biggest mistakes you can make is to keep fartingaround with the dose because you think you can control it. That's a mistake. Keep a steady hand on the tiller and adjust only as needed. Its especially variable in the first year after surgery.

Here is last years as a reference

my surgeon and physician both think its a good result and "stable". Note that the small range on the Dose Y axis makes it look like I fiddled my dose more than I did ... the range is really all between 7mg and 8.5mg. Note also how my greatest variance occured when I had a go at micro managing it on day 10.

Best Wishes

 

[dreamwarrior13]

Thanks. Yeah, I learned (albeit slowly) to calm down a bit and not worry so much about it going up and down -- the biggest frustration about it doing that for me is just that it means more frequent trips to the clinic for testing. Unfortunately they aren't so liberal regarding their definition of stable -- I'm supposed to stay between 2.0 and 2.5, or at the least, 2.0 to 3.0, or else it's considered "out of range" and I need to adjust my dose and come back sooner rather than later for the next test.

 

[LondonAndy]

Is there a reason you don't self-test Dreamwarrior13? Would stop most of the trips to the doc/clinic, and research has found greatly reduced bad events by doing so.

 

[pellicle]

Hi

.... Unfortunately they aren't so liberal regarding their definition of stable -- I'm supposed to stay between 2.0 and 2.5, or at the least, 2.0 to 3.0, o

2.0 and 2.5 is more or less impossible, 2.0 and 3.0 is what I'm between 98% of the time. As you can see in the chart above when its gone out of those bounds its always returned with zero intervention. But of course I always monitor 3 days after i get that reading so that I can decided if action is needed. The clinic method where they react first and follow up later is exactly what causes that sort of instability in the left hand side of the graph.

 

[pellicle]

Is there a reason you don't self-test Dreamwarrior13? Would stop most of the trips to the doc/clinic, and research has found greatly reduced bad events by doing so.

Andy

from what little I have gleaned about the USA system is that its more tied down than a Spanish Bondage hotel when it comes to allowing people to be adults with their medications. I suspect a huge industry disinclination to effect the sorts of monetary savings which are driving European countries to instigate self testing because then the clinics would not be able to charge the health funds $200 per test. Add to this that people are already de-capacitated there isn't the willingness to learn how to "when someone already does it for them"

just my (probably overly cynical, colonial boy influenced) interpretation

 

[LondonAndy]

Ah. I bow to your superior knowledge of Spanish Bondage hotels Pellicle!

Here in the UK it is patchy: my doc was very supportive of self-testing (in England you have to buy the INR meter, then test strips are available on prescription), but a colleague at work cannot get his doc to allow him to self-test, even though he is mentally and physically very competent. It is only recently (Sept 2014, coincidentally when I havd my AVR) that our national regulator has published guidance strongly recommending self-testing for improved outcomes, so although I am the only one that my doc knows doing this at present I am sure numbers will rise over time.

 

[tom in MO]

Hi



2.0 and 2.5 is more or less impossible, 2.0 and 3.0 is what I'm between 98% of the time. As you can see in the chart above when its gone out of those bounds its always returned with zero intervention. But of course I always monitor 3 days after i get that reading so that I can decided if action is needed. The clinic method where they react first and follow up later is exactly what causes that sort of instability in the left hand side of the graph.

You regularly state that 2-2.5 is not possible to maintain. I've done it for 3 years. It's the recommended range for St. Jude mechanical valves, so I am pretty sure that I am not the only one

 

[pellicle]

Hi Tom

You regularly state that 2-2.5 is not possible to maintain. I've done it for 3 years. It's the recommended range for St. Jude mechanical valves, so I am pretty sure that I am not the only one

You are correct, my wording should more accurately be an unnecessarily narrow range that for quite a many people will not be attainable.

But I think its an acceptable shortening for a public forum when not trying to sound "up myself" with long sentences.

You can see my dose is regular and you can see my testing is regular and you can see my INR wiggles around between 2 and 3.

Do you alter your dose to maintain that range or is it just what you get? Perhaps you are simply lucky?

My point is that if that's your metabolism then great but equally others will be different and thus if you are different then don't force yourself to fit into a box that you can't fit into.

What do you propose should be done differently to achieve your results?

 

[MethodAir]

I have an On-X valve, I'm ok if I'm anywhere from 1.8 to 2.8. I try to be in the low 2's but if I'm a little higher one week, so be it. I started at a Warfarin dose of 2.5mg after surgery, and was around 2.5 INR. Since adding more cardio, and a lot of fish oil (12 teaspoons of Carlsons), I take 6-6.25 mgs per day. The cost of test strips makes more frequent testing an issue (around $10.00 CAD per strip).

 

[pellicle]

Hi

... The cost of test strips makes more frequent testing an issue (around $10.00 CAD per strip).

I'd argue (in support of your point above) that unless you are interested to learn about it (as I am) that testing more than once a week yields little benefit in the long term.

FWIW I buy my strips online at about AU$5.60

 

[MethodAir]

Makes sense. I would reserve the extra tests for times when I anticipate breaking out of the pattern (by adding or subtracting a lot of fish oil for instance).

The reading of 3.8 on the 12th was a signal to begin what I call an Adhoc monitor, where I increase the INR tests from weekly to twice a week.

http://cjeastwd.blogspot.ca/2015/10/managing-my-inr-example.html

 

[W. Carter]

This study of 250 patients that had steady inr readings for 6 mo. Did just as well getting their inr tested every 12 weeks. as getting it tested every 4 weeks. I am going on the same dose for 4 mo. (42.5 mg weekly) and my inr ranges between 2.5 and 3.5. I guess that would be considered steady in this article. Too many anticoagulation clinics jump the gun and change the dose when it is really not needed because of testing too often on steady reading patients. I agree with the study, lets say in a 12 week period your inr fluctuates between 2.0 and 4.0 this is not going to effect your valve or health at all. If you are getting tested every 2 or 3 weeks and they see fluctuations such as these they will be changing your dose up all the time.
http://professionalsblog.clotconnect...inr-be-tested/

 

[dick0236]

This study of 250 patients that had steady inr readings for 6 mo. Did just as well getting their inr tested every 12 weeks. as getting it tested every 4 weeks. I am going on the same dose for 4 mo. (42.5 mg weekly) and my inr ranges between 2.5 and 3.5. I guess that would be considered steady in this article. Too many anticoagulation clinics jump the gun and change the dose when it is really not needed because of testing too often on steady reading patients. I agree with the study, lets say in a 12 week period your inr fluctuates between 2.0 and 4.0 this is not going to effect your valve or health at all. If you are getting tested every 2 or 3 weeks and they see fluctuations such as these they will be changing your dose up all the time.
http://professionalsblog.clotconnect...inr-be-tested/

Interesting article.....but I would be very hesitant to go three months between tests. I actually did this for about a year in the 1980s (with my docs approval) with no adverse problems. That same doctor was horrified a year or so later that he had suggested the 3 month routine.....go figure. There is a lot that can go wrong in three months......bad pills, significant dietary changes, medicine interaction, forgotten pills, etc. and it only takes a few days, at least for me, of significant INR change to cause a stroke......been there and done that and I don't want to do it again. While I'm beginning to think that weekly might be too often (if your INR is stable) I would not go more than one month between tests.

 

[LondonAndy]

This study of 250 patients that had steady inr readings for 6 mo. Did just as well getting their inr tested every 12 weeks. as getting it tested every 4 weeks. I am going on the same dose for 4 mo. (42.5 mg weekly) and my inr ranges between 2.5 and 3.5. I guess that would be considered steady in this article. Too many anticoagulation clinics jump the gun and change the dose when it is really not needed because of testing too often on steady reading patients. I agree with the study, lets say in a 12 week period your inr fluctuates between 2.0 and 4.0 this is not going to effect your valve or health at all. If you are getting tested every 2 or 3 weeks and they see fluctuations such as these they will be changing your dose up all the time.
http://professionalsblog.clotconnect...inr-be-tested/

Thanks for the link to that study, which showed a 'time in therapeutic range' of 74.1% for those testing a 4 week intervals, and 71.6% for those testing at 12 week intervals. If you are happy with being out of therapeutic range for between a quarter and almost a third of the time then so be it, but with the help of weekly self-testing I have been in therapeutic range for 94% of the last year. Does that matter? Here's what the English national regulator, NICE, had to say in September 2014:

"Twenty one trials reported 351 major and minor thromboembolic events in a total of 8394 participants. Self-monitoring (self-testing and self-management) showed a statistically significant reduction in the risk of thromboembolic events by 42%". http://www.nice.org.uk/guidance/dg14

So in other words, a much larger study (8394 patients compared to 250 patients) showed a 42% reduction in thromboembolic events because their INR range was managed more tightly. THAT IS OF HUGE IMPORTANCE. Testing does not cause problems, it simply provides facts on which better decisions can be taken, but I agree the interpretation of those results, and decisions on changes to dose, are very important. Having the ability to undertake these tests reliably at home rather than the inconvenience (and higher cost) of going to a clinic, and increasing the frequency of testing when things change, is incredibly valuable for some of us. However, that is not to say 12 week intervals between tests is always bad - in the same report NICE states this is an acceptable frequency for those who have had a stable INR for a long period. I am not sure I will ever leave it that long myself.

 

[dick0236]

Thanks for the link to that study, which showed a 'time in therapeutic range' of 74.1% for those testing a 4 week intervals, and 71.6% for those testing at 12 week intervals. If you are happy with being out of therapeutic range for between a quarter and almost a third of the time then so be it, but with the help of weekly self-testing I have been in therapeutic range for 94% of the last year..........
.............. However, that is not to say 12 week intervals between tests is always bad - in the same report NICE states this is an acceptable frequency for those who have had a stable INR for a long period. I am not sure I will ever leave it that long myself.

Great "counter point" post.......that's why I continue to stay on this forum. Good "pro and con" info.

 

[pellicle]

Hi

This study of 250 patients that had steady inr readings for 6 mo. Did just as well getting their inr tested every 12 weeks. as getting it tested every 4 weeks. ... Too many anticoagulation clinics jump the gun and change the dose when it is really not needed because of testing too often on steady reading patients.

I agree with this, but would add that its not because of testing too often, its because of bad decision making. Having more data is never the cause of bad decisions. I (sorry can't think of a better word) hypothesise that the cause for the bad decision making is a combination of not having any knowledge and "fear of litigation due to duty of care" ... A litigant could argue that because they had data and took no action that my bleed event was contributed to by you.

So extend your sampling and the peaks and troughs seem to hide. Try just taking 12 week points in my graph above, see what you get.

My view is that these bozos lack any methodology and any actual algorithm for decision making. I refer to a PhD thesis comparing computer algorithms (which are based on INR being a random thing) and clinics. It came down to the algorithm being better than all but the most experienced clinicians. Is that clinician trained in anything? I doubt it because (working at a University) I know there is generally nothing they can be trained in because we (here) have no specialised training for INR management. INR management is a "heuristic" gleaned by "professionals" who are trained only in the tools of measurement and in basic pathology. They gain their experience by interest and obvservation. (what if they are not interested?)

In my blog post http://cjeastwd.blogspot.com/2014/05...ocks-dose.html I propose an algorithm which I have found works. I prefer to keep the details of that a little close to my chest because I would like to write software based on it.

I have in the past sought data from people to test the transferability of that data but have never had any responses. I assume because no one is organised enough with their data.

 

[pellicle]

Hi

... However, that is not to say 12 week intervals between tests is always bad - in the same report NICE states this is an acceptable frequency for those who have had a stable INR for a long period. I am not sure I will ever leave it that long myself.

great post, its nice to have a rigorous researcher here.

I had been feeling the same and was considering streching my testing out to 2 weeks but two factors stayed my hand:
1) the packs of 24 strips I buy would expire by then, meaning I would not save money in the long terms
2) I stumbled across this little 3.8 event I was having and was glad I did something about it. It could have gone to over 4 and it could have contributed to harm (but didn't because I didn't let it get over 4)

The medical community uses the term patients ... I wonder if it should not perhaps be subjects. (or on a more cynical day I may say "victims in waiting")

 

[W. Carter]

pellicle On your graph in any 12 week period your inr is 2.1-3.5 except the one spike to 3.8 which is still not dangerous. The 2.1-3.5 are all safe numbers for a mechanical valve. The graph just proves my point that 12 weeks can be safe in people that have managed their inr and have become stable. Early on while getting use to warfarin I had spikes to 7.0 and i'm still here and not brain dead. They did drill 2 holes in my head but I guess they missed my brain.

As far as 4.0 or a little higher being dangerous there are people with mitral valves that their inr range is 3.0-4.0, so of course their inr ranges from 2.5-4.5 quite often with no harm.