INR Home Monitoring

[DottyCece]

I have been recently approved by my insurance company for a Home INR meter.  My device is a Protime Microcoagulation System manufactured by ITC.  The curettes have five channels.  Anyway, after I got approval and learned how to do home testing correctly, my cardiologist became concerned about the variance between the lab results and my results. I am the first patient he has who has or is doing home testing.   My results to date vary by 0.4 (higher) from the lab results. I have read a lot of research on this topic and it is evident that there is variance between labs as well.  What is your opinion on the use of home INR monitors?  Does your center promote the use of these for prosthetic valve patients?  I was approved because of my valve and the fact that I was out of target range greater than 50% of the time.

I was so excited to be doing home testing and having control over this part at least. Now I don't know if I can have confidence in my home results.  I do not want a stroke or bleed etc. etc.

[CCF-M.D.-MJM]

Hi Dotty,

This is a very good question, in fact it came up in my clinic just last week.

Practically speaking, home testing is a very good idea.  It will cut down on the costs, is more convenient for you (the patient), and gives more control to you as a patient.  For the most part they must be same and accurate because they are taking a huge financial risk if they are not.  Coumadin can be a dangerous medication if not controlled properly. Corporations are aware of this and would not release the machine if they knew they weren't accurate.

What makes me uncomfortable is I lose control over your labs.  It is nice having them in our own system.  For example, the standard of care is to have a therapeutic INR for at least 3 weeks prior to cardioversion.  If they aren't in my system how do I check?  If they are from your monitor and the control is off and you have a stroke after cardioversion, whose fault it is –the machine manufacturer, yours or mine?  I wouldn't want to be the test case to figure this out -- no one wins.

The truth is that I think this is the way health care is heading -- more home testing.  I think overall it is a good thing, but there are some issues that need worked through.  I am hesitant to embrace it yet and certainly voice this to my patients (like it sounds like your doctor has done), but I do not tell them they can't do it.

I hope this helps a little bit, I know my answer is less than definitive.  Good luck and thanks for posting.

[DottyCece]

Thank you for your kind answer.  I wish I had the opportunity to talk with you further about this. I was so thrilled when I was approved for the device but now I am less than confident.  My device has a built in high and low control in each curvette.  Also, the test is done on three channels so the result is not dependent upon only one channel.  What I am doing though is testing each week at home and having a lab draw every three weeks.  Dosing is based on the lab results.  After a few months we will need to decide how to proceed.  I am keeping my cardiolgist's office updated with my home test results. I would have a lab test every few months if I home tested to make sure my meter was okay.  For procdures, I would do a lab test and rely upon that.  There is so much in the literature that says there are variations about labs as well.  If I had four labs do the test on the same blood, there would be foour results.

I have collected a number of research studies that I have given to my cardiolgist.  I understand his reluctance but I think there is a safe way to do this.    

[Lyn2]

Great Question!  
I have been questioning the idea of a home monitor for quite sometime.  Everytime I bring it up at the cardios office where I am tested I get it would be too confusing, or the test strips are outrageously expensive.  Really, no logical answer that I can understand.  I guess I was comparing it to blood sugar.  Diabetics do home monitoring on a daily basis and that is a life and death deal as well, so I didn't understand why home testing of INR was so different.
The doctor here helped explain it from the perspective of the medical profession.  Still, if the opportunity presents itself I would love to do the home monitoring.  At this point I have to go get tested every couple weeks, and it gets time consuming.
Good luck with yours Dottycece.

[DottyCece]

They think it is too confusing because they are not comfortable with it and don't understand how it works.  ITC has gathered a lot of independent research on this topic.  They will send them to you and you can pass them on to your MD.  There are forms on the QAS website you can download to fill out and see if the insurance company will cover you.  Your MD has to sign the prescription.  The cuvetts are expensive ($13) for each test.  But compare that to the lab fees and your loss of time etc. and then it isn't so bad.  These test strips are not at all like the diabetics.  My test strip (cuvetter) has five channels with one that is low control and one high control.  The test is then run on the other three channels so the result is not based soley on one channel insteach on three channels where a light senses the coagulation.  I think if this is successful, you still have to communicate and work closely with the MD office.  As the Dr. said, coumadin is a dangerous drug and you really have to be very careful.  Good luck to  you.