Home INR Testing

[Jimmyk]

Today I spoke with a woman who works with the Coumadin Clinic that I used to go to.
When the topic of home testing came up, the was totally against it. She told me that everything I use was off the black market.
She asked about the calibration of my machine, possibly getting defective strips, ect.....

Question, Has anyone ever had their machine checked for calibration ?

 

[pellicle]

Today I spoke with a woman who works with the Coumadin Clinic that I used to go to.
When the topic of home testing came up, the was totally against it.

gosh ... I'm surprised ... look up the meaning of "Vested Interest"

She told me that everything I use was off the black market.

ahhh hahahahah ... what ******** is that ...

Question, Has anyone ever had their machine checked for calibration ?

there was calibration with the S but the XS has this built in. I believe that calibration is built into the system at manufacture (thus the batch related chip shipped with those stips)

I myself simply compare the results with what the lab gives me, which I do periodically (and have posted same here). I believe that is prudent.

In the time I've been doing that I (like many) have never seen a clinically significant difference.

America is turning health care into a business where the patients interests are not served but the patients are charged. So while the rest of the world is moving towards self testing, the clinics who bill $100 per test (which you could do for 6) are really becoming obsolete for that particular test (in the volumes they are doing it int). Ask how they do the test and if they use an iStat ... (which is the same method and chemistry as the coaguchek XS)

I find it interesting that clinics are regularly lambasted here for doing a **** job of managing you but as soon as one of those same clowns tells you "Oh I wouldn't trust that, come to us" everyone just sees the white coat and things of them as holy priests.

I change my own oil in the car too.

 

[pellicle]

PS she is probably referencing publications which are greater than 10 years old.

And I'm sure she'll want you to believe that being managed by them with monthly testing will be better than you managing yourself

https://www.cadth.ca/sites/default/f..._poc_inr_2.pdf

which I find amusing because the cost column is some insane number for patient self management.

I pay $180 for a packet of 24 strips which I use two of per year. So far my machine has lasted since 2012 with (more frequently than) weekly testing

 

[pellicle]

also, point 2 of the FAQ

http://www.coaguchek.com/coaguchek_hcp/en/home/training_and_support.html

but thanks for the morning laugh ... I'm still getting a giggle ...

 

[LondonAndy]

Yes, I get my meter calibrated every six months at my anticoagulation clinic. I am in my fifth year of self testing, and on the same meter since day one.

With apologies for posting this link again, here in the UK self testing is promoted as the current "gold standard" of managing Warfarin. The ability to test more frequently than clinics typically offer (I test weekly, clinics here typically test every 4, 6 or 8 weeks when a patient is considered "stable") means I spot when I am out of therapeutic range much more quickly than they would. The result is a "lower risk of death", and of serious complications like strokes. See this amateur note I prepared for my doc of some key points from the 2014 report by the UK's "National Institute of Clinical Excellence".

 

[pellicle]

Yes, I get my meter calibrated every six months at my anticoagulation clinic. I am in my fifth year of self testing, and on the same meter since day one.

very interesting ... how?

Great summary doc ... mind if I cite that on these sorts of threads (crediting you of course)

 

[ForeverThankful]

I do the same as many people here, once in a while I compare a result from my meter to a result from a lab draw at a nearby hospital that specializes in heart surgery . The last couple of times I compared them they gave the same result or a result with 0.1 difference.

I have two meters, one I bought on Ebay about a month after surgery and one that was supplied from Coagucheck through my insurance company. I generally use the one I bought myself. I buy strips on ebay and get some strips from Coaguchek through insurance. It never occurred to me that the ebay strips and ebay meter were "Black Market", the woman you spoke to is either ignorant or afraid she'll lose her job!

One thing I've learned after taking warfarin for three tears is that most people in the medical field have no idea what they are doing when it comes to warfarin dosing.

 

[LondonAndy]

very interesting ... how?

Great summary doc ... mind if I cite that on these sorts of threads (crediting you of course)

Like ForeverThankful, I do a self-test at the clinic and they do a blood draw, and then they email me later with the results. Sometimes the comparison is with their own CoaguChek machine - the policy seems to change each time I go!

And yes of course, no problem for anyone who wants to use the document.

 

[LondonAndy]

I do the same as many people here, once in a while I compare a result from my meter to a result from a lab draw at a nearby hospital that specializes in heart surgery . The last couple of times I compared them they gave the same result or a result with 0.1 difference.

My comparisons have also been either 0.1 or 0.2 different to the clinic's. Generally my meter's reading is higher than the lab result, though once was lower.

One thing I've learned after taking warfarin for three tears is that most people in the medical field have no idea what they are doing when it comes to warfarin dosing.

I agree! I was slightly over my therapeutic range recently, on a week when I was due to send a reading to the clinic. (I test weekly but they only ask for a reading every 6 to 8 weeks). The clinic's advice was for a much greater dose reduction than I considered was needed. I followed my own instincts and was soon back in range.

 

[Warrick]

I do a side by side test at the lab every now and then as they also use coaguchek meters and last one was bang on the same,
here (NZ) the entire population of my country fits in one city in most major countries, and there are 38,000 people in nz on warfarin so it sounds lucritive at $100 a test compared to what I pay at $7 nzd a strip.

I googled “black market coaguchek test strips” and nothing real came up so sounds made up to me, if roche make the strips and distribute them to retailers and then they onsell them how they see fit without massive mark ups then its a win for us.

 

[pellicle]

Like ForeverThankful, I do a self-test at the clinic and they do a blood draw, and then they email me later with the result

but that's not really calibrating the instrument ... its more a double check against another reference right?

Calibration is where you adjust the output based on known references, so you're not able to "change" the output of the XS based on this reference ...

 

[Jimmyk]

Pelicle, I have an XS machine..I once tested it and compared it to a blood test. I believe it was off.1 which in my opinion seems very accurate.
I’m going back to the testing method that worked the best.
I’ll use my own machine, buy strips and test once a week.
I learned a lot from your blog when I first started self testing.
Unfortunately, I’ve been self paying for medical insurance. As of January 1st , any hospital stay, the price on my end has quadrupled.
I’m walking an hour a day again, waiting on news about going back to work. Trying to be optimistic about the future!

 

[Jimmyk]

Pelicle, I have an XS machine..I once tested it and compared it to a blood test. I believe it was off.1 which in my opinion seems very accurate.
I’m going back to the testing method that worked the best.
I’ll use my own machine, buy strips and test once a week.
I learned a lot from your blog when I first started self testing.
Unfortunately, I’ve been self paying for medical insurance. As of January 1st , any hospital stay, the price on my end has quadrupled.
I’m walking an hour a day again, waiting on news about going back to work. Trying to be optimistic about the future!

 

[Jimmyk]

ROCHE supplied me with a machine though insurance, they now want it back. It’s the newer model, with all the bells and whistles.
The xs has never failed!!

 

[tom in MO]

Like ForeverThankful, I do a self-test at the clinic and they do a blood draw, and then they email me later with the results. Sometimes the comparison is with their own CoaguChek machine - the policy seems to change each time I go!...

That's not a meter calibration. That's a comparison of results or a comparison of analytical methodology. A comparison of results by two different meters has nothing to do with the device calibration of one method. It's not even a calibration check. If they don't agree, you have no reason to blame the meter calibration. If they don't agree within a tolerance set by historical data, then it's time to investigate. Once the cause is found, then you blame the cause. To complicate it more, don't forget, the meter's accuracy and precision capabilities changes over the meter's operating range.

IIRC, the "reference" for INR meter measurements is one or two laboratory methods, not another meter. They may have you do that comparison to make sure you are using the meter correctly, not to check the meter. The biggest error (for me) with the INR home testing machine is operator error and I'm a technical person, nowhere near 90 and can see pretty good. Even if for the comparison they take blood for testing, the laboratory doing the testing might not be using the "reference" INR method, they could be using a meter in the lab too.

If you buy INR testing supplies on E-bay, make sure they are an authorized supplier and not some family member of a deceased relative who was on warfarin. The way the testing strips are handled is important to good test results, it's called supply chain control. In addition, when there is a recall, like what just happened, an authorized supplier will be able to find you, tell you of the problem and its risk plus replace your defective strips. The guy who is selling his dead grandma's testing supplies on Ebay won't care.

 

[pellicle]

Hi

Pelicle, I have an XS machine..I once tested it and compared it to a blood test. I believe it was off.1 which in my opinion seems very accurate.

agreed , to clarify another phrase I use here, "Clinically Significant" , that's certainly not significant to make a change in a clinical assessment of your INR and if it needs responding to.

I’m going back to the testing method that worked the best.
I’ll use my own machine, buy strips and test once a week.

that's a good strategy. I would simply buy strips in bundles of 24 and use them, ordering new ones when down to the last 5 or so.

I don't buy significantly in advance as 1) they expire 2) subsequent notifications of recalls may occur (as we experienced recently) and you may have an effected batch.

I learned a lot from your blog when I first started self testing.

happy to help fellow valvers ;-)

Unfortunately, I’ve been self paying for medical insurance. As of January 1st , any hospital stay, the price on my end has quadrupled.
I’m walking an hour a day again, waiting on news about going back to work. Trying to be optimistic about the future!

I'm glad to hear all that (especially about the work and optimism.

On the earlier subject of your aneurysm, I would always take the counsel of medical professionals as being said in the most cautious manner of phrasing it. I can say I've almost never done exactly what I was cautioned not to do because I'd rather be dead than live in a cotton wool lined closed box (with a window).

I always payed careful attention to my own limits and reflected carefully on any life threatening ventures (such as ski and sled trips which may pass through avalanche areas or motorcycle racing).

I was fortunate that my Dr said not to do "Competitive Sports" (when I was a teenager) but doing them socially was fine (he understood the difference between pro-football and a game with mates. I trained regularly and took up cycling with gusto after my 2nd OHS. I used a HR monitor to track my HR and made sure that my progress was "steady but not aggressive". Recently I've changed my walk from around town to a track down through Queen Mary Falls. Its short but the inclines give me a warm up (on the way down) and allows me to pick my HR pace on the way up. I often stop at the bottom to say "Hi" to the locals

 

[LondonAndy]

but that's not really calibrating the instrument ... its more a double check against another reference right?

Calibration is where you adjust the output based on known references, so you're not able to "change" the output of the XS based on this reference ...

You (and Tom) are of course quite right. It is not calibration, just a comparison, and I have lapsed into the slightly patronising language the clinic uses. I also agree with Tom (and of course Pellicle will agree) that there are variables with the lab tests too, so if they ever do show a significantly different result I certainly won't be throwing my machine away. Instead a further test comparison would seem appropriate.

 

[pellicle]

Hey Andy

You (and Tom) are of course quite right. It is not calibration, just a comparison, and I have lapsed into the slightly patronising language the clinic uses.

I didn't mean to be patronising myself (sorry if it came across that way).

Myself I wouldn't care if I got a few "errant readings" and unless there is a demonstrated systemic fault with the Coaguchek I'll be using it for the forseeable future.

On the point of labs and Coaguchek disagreement, if such occurs its worth investigating why (you may have a blood disorder for instance), but even 0.5 INR points away from the lab is not in itself telling.

Its like the joke about the railway station that has two clocks, one on the platform, the other in the waiting room. They both show different times, so the passenger asks the station master "Did you know that you have two clocks and they both show different times"

"Yes Sir, otherwise we wouldn't need two clocks Sir"

;-)