Weekly Testing

[Protimenow]

As many of you already know, I test with more than one meter. I also, in the past, have compared my meters to lab results. I've also compared two labs with blood drawn on the same day a few hours apart.

I have been fairly comfortable with the strong sense that - even though my meters don't always agree (and in some cases aren't even very close) - I'm still in range.

I test weekly. Some meter manufacturers also suggest weekly testing. I strongly advocate for weekly testing - even though some in the medical community (including anticoagulation clinics) are still fine with testing every month - or two - or even three.

For the past many months, my INR has been in range. I try to keep between 2.5 and 3.5, even though one doctor said 2.0-3.0 is where my INR should be for my aortic valve.

Although I've been in range for months -- today my weekly testing surprised me. My Coag-Sense meter gave me a 1.8 -- a troubling value, especially considering the fact that I had a TIA a little over a year ago because of my INR going too low and my testing not being often enough (and my reliance of the absolute accuracy of my meter). Although I'm following the stroke protocol in place at the hospital where I have been getting some medical care (Lipitor, whether I need it or not), and presumably are at less risk of a recurring stroke, I don't want to take any chances.

My test with a Coaguchek XS just seconds after the Coag-Sense test gave me a slightly more comforting 2.3 -- still a little below my comfort range. My InRatio gave me a 2.4. The InRatio and CoaguChek XS have been coming in very close to each other, now that I know to get a bigger drop on the InRatio strip than I may have in the past.

As a result of the drop in my INR, I decided to still be a bit conservative and make a small increase in my dosage - with a bit of a hike for today. I usually take 7.5 mg daily at bedtime. This time, when the low INR was observed, I took 7.5 MG earlier than usual, and followed up at bedtime with 4 mg. I have no insurance, so I couldn't bridge even if I wanted to.

My INR about 8 hours after my first set of tests, using a Protime 3 with a 5 channel cuvette (arguably the most accurate test available) was a 2.0--at the bottom of the range, and .5 below my minimum comfort level.

I am increasing my dosage from 7.5 per day to 8 mg/day -- not a big spike, and not one that I didn't take in the past. With my extra 4.0 mg today, I fully expect my INR to be back in range in two days.

My point is this: I've done nothing that should have changed my INR. I didn't forget my dose of warfarin. If I was testing monthly - or took comfort in the many months of test results that were in range, I would have missed my drop to (or below) around 2.0. If I hadn't made a minor adjustment in my dosing and remained at or below 2.0 for another week - or two - or three, I don't even want to consider the possible consequences.

It's the weekly testing that lets us know our levels. It let me know that my INR is low NOW, but may have been low for nearly a week. It gives me time to make the correction. A test every month WON'T.

That's the main reason that I test weekly. I'm confident that my 1/2 dose boost today, and slight increase in dosage going forward is enough to quickly bring me out of danger.I'm glad that I found the issue and was able to respond to it before it became a REAL issue.

I'm interested in YOUR response to my position - PRO or CON.

 

[gerrychuck]

Pro. You have stated the logic behind your routine very well. I also test weekly, although I feel somewhat inadequate with my single little meter

 

[pellicle]

Hi

I'm interested in YOUR response to my position - PRO or CON.

assuming your "position" is test weekly, then I'm for this position. I also test weekly.

My point is this: I've done nothing that should have changed my INR. I didn't forget my dose of warfarin.

yes, it does happen. Mine has gone up and then down and I have adjusted dose ... if I didn't adjust the dose I don't know where it would have gone to before it stabilised.

I doubt that it fluctuates so wildly that I need to test more than weekly.

I'm confused by your reporting:

My Coag-Sense meter gave me a 1.8

then

My test with a Coaguchek XS just seconds after the Coag-Sense test gave me a slightly more comforting 2.3 -- still a little below my comfort range. My InRatio gave me a 2.4.

which I assume means you wanted to write:
I tested with Coag-Sence and got 1.8, and just seconds later the test with the Coaguchek XS gave 2.3. Then "some time" later the InRatio gave 2.4.

I just find your sequence hard to follow. It would make it clearer to me at least if you listed it. I have to dig back and forwards to see what you want to say. So is it:
test 1) Coag-Sence = 1.8
test 2) Coaguchek XS = 2.3
test 3) InRatio = 2.4
test 4) Protime 3 = 2.0 [performed some 8 hours later]

Did I get that right?

You often say you wish to inform people, but for me at least digging through your posts is difficult. Your evidence is presented in a scattered manner. It makes comprehending what you say difficult and its easy to just skim through and dismiss.

If you do wish people to be assisted by what you write, I wish you would make your procedures sequenced clearly.

 

[Protimenow]

Your sequencing is correct. However, the 'some time later' for the InRatio 2 was perhaps 5 minutes. That's the reason that I put them in that order.

It certainly would have been easier if I listed them in the manner that you used.

In an earlier post, I noted that the CoaguChek XS and the InRatio 2 have been consistently either the same or within about .1 of each other. (Neither meter has matched the ProTime or Coag-Sense, so far). Right now, I'm not able to get a blood draw to compare with my meters. Without this 'control', I probably just have to comfortable with no meter reporting a result that was at the bottom of, or below, my minimum.

Gerrychuck: One meter is plenty if you're confident in its accuracy -- or know what adjustments to the numbers you'll need to make in order to be certain that your INR is always in range. If your meter is always .6 higher than the lab values, or is a certain percentage higher (or lower), then you should be able to convert your meter's results into approximate lab results.

I have acquired more than one meter for a few reasons. I was looking for something that was easier to use than the Protime and Protime 3 -- I was fortunate to get a Coaguchek S a few years ago (slightly easier), and soon after that, got an InRatio. The InRatio was certainly more compact and somewhat easier to use - and I put a lot of (misguided) faith in its accuracy. I had a minor stroke, in part, because I thought that the meter was completely accurate (and wasn't).

Not wanting another stroke, I decided to keep a closer eye on my INR, and it's a quest to find the most accurate (or perhaps most reliably inaccurate) meter. When I was able to get a Coag-Sense inexpensively, I got it because the testing method sounded like it may be more accurate than the inRatio. When I was able to get a Coaguchek XS inexpensively, I jumped at the chance.

The difference from the results of the Coag-Sense and ProTime 3 and the results reported by the Coaguchek XS and InRatio seem to suggest that there may be something going on in my blood -- that there may be factors that result in higher reported INR from the InRatio and Coaguchek XS than lab values, or, conversely, that there's something that would make the Protime and Coag-Sense report lower than actual values. This kind of perspective would be unavailable unless more than one meter is being used.

When/if I get another blood draw, I'll probably ask that they check my hematocrit (which might 'confuse' one or more INR meters).


But, as I said earlier, having one meter, and learning its necessary (adjustments) should give you the power to keep track of your INR. For myself, I'd like the meter that reports the lowest value to STILL report one that is in range. If my INR is at the higher ends of my range, I am not particularly concerned about it.

 

[chaconne]

I generally try to test weekly, although this week I forgot to do it on Sunday and will hopefully remember tonight. I agree that it's better to know where the INR is, more often then not. When I'm out of range on a lab draw, however, they will test more often as well. It's been 6 weeks for lab draws lately, but if I was out of range, the might follow up in 1-2 weeks.

 

[Protimenow]

I just don't understand the 'if you're in range, we don't have to test as frequently' argument. Each test is a snapshot. It tells what the INR is AT THE TIME THAT THE BLOOD IS DRAWN. It doesn't telll you anything about what may be happening between draws.

Look at it this way: let's assume that you get your hair colored every month. During the month, it gradually goes from black to a dark gray. If they take a photo of your head once a month, they'll conclude that your hair is black. 'Hey, it's been black for the past two months -- we'll see you in two months.' This monthly snapshot has no way of determining that the color diminishes for the days after the photo is taken. A photo that is taken weekly will show the changes.

Now, I'm not saying that hair color and INRs are equivalent -- but what I am suggesting is that your INRs may differ significantly between tests. If, for example, you get your monthly blood draw, then miss a couple doses in the next week, a monthly test won't pick it up. A weekly test has a much higher likelihood of finding any issues with higher or lower INRs.

(Although I went for long periods between testing, years ago, concluding that the dose that I was taking was always going to keep me in range, I now strongly believe in the value of weekly testing)

 

[pellicle]

I just don't understand the 'if you're in range, we don't have to test as frequently' argument. Each test is a snapshot. It tells what the INR is AT THE TIME THAT THE BLOOD IS DRAWN. It doesn't telll you anything about what may be happening between draws.

I can only assume that some people do remain very stable. But its an assumption that doesn't hold for me.

Perhaps its from a time when testing was difficult and expensive. People are slow to change their thinking.

 

[chaconne]

I wonder if there are studies comparing those who are tested weekly vs. up to monthly to see if one or the other has a SIGNIFICANT advantage avoiding strokes or bleeds. I think it would be difficult to do a fair comparison because those who test weekly are usually home testers and pay much more attention, in general, to their levels. Maybe you could get a group of home testers and a separate group who only does lab testing. In each group have those who test weekly/up to monthly.

It seems logical that there must be some difference between the two, but I'm still unsure which is better/worse on average. Weekly testing may catch unseen changes in INR, but testing too frequently may tend to lead to roller-coaster INRs (assuming self-dosing). Monthly may work for some better than others, patent input about changes in diet and lifestyle is an input parameter that can negate the need for more frequent testing. For me, I prefer to have more information, which is why I test weekly. I do not self-dose at this point, but I want to be trained and prepared to do it if the need arises.

 

[Gail in Ca]

Yes, I also test weekly. It has been proven that people who test weekly stay more in range. I was shocked to hear the Coumadin clinic nurse at my HMO say that the new guidelines will probably be for people to come in and test only every 6 weeks, up from once a month! Is this government health care? If so, I don't want it! Thankfully, my cardio wants me to test weekly, and so I get my supplies covered for that. But, I would question your use of numerous machines. I would recommend sticking with one machine that you feel is the one that gives you a reading closest to the lab. When I used my Protime 5 channel, that's all I used. When I did a check with the lab, it was always within .2 of the lab results. My Coaguchek XS is now the only one I use, even though I have a Protime in the closet.
I also have a ? for people who get their strips from sites like e-bay. Are you comfortable getting strips from an unknown source? I ordered Coaguchek XS strips from e-bay and used all 48 with seemingly no problems.
But, when I mentioned to Alere that I got them off e-bay, she wanted to tell her supervisor, and sort of made me worried about it, darn it! So, I got my last order from Alere.
Are you all comfortable with your source for strips?

 

[Protimenow]

Gail:

I am perfectly comfortable getting my strips on eBay. The strips have quality controls built into them, and if there's a problem, it's more than likely that the QC on the strips will reveal the problem.

From what I've heard, Alere prefers to sell directly - they make more money this way - and injecting a bit of doubt about strips bought from another source obviously works.

One thing that none of the manufacturers tell you is that the strips that 'don't require refrigeration' actually might require it if the temperature where you're storing the strips goes above 90 degrees. I asked Roche about it a couple days ago -- the temperature in my house was probably 100 or higher (I don't have air conditioning), and the Roche representative couldn't tell me how long the strips would be good in temperatures above 90 degrees.

I have gotten strips from various sellers on eBay -- from people who had to test their INRs for other conditions and no longer need the strips; people who apparently inherited the strips from a person who died; strips from sellers of medical supplies who specialize in strips -- and all have been good. The results correlated with other machines and occasionally with the labs.

The only 'bad' set of strips that I had came from a medical supply company (not on eBay). I reported suspicious results to the manufacturer and a few months later, the supply company told me about a recall on the defective strips. The bad strips were replaced. This experience may reveal an important point with reference to your source of the strips. Because the bad strips were bought from a retailer - the retailer was able to look up my sales record and inform me of the recall and, eventually, to replace the bad strips. I'm not sure if a company that sells on eBay would have a system for notifying its customers of recall actions.

For myself, I've had no trouble with strips that I bought on eBay. I haven't hesitated in buying more strips. If your dealer provides a retuen policy, you should feel pretty safe about ordering the strips on eBay -- at least, this is what personal experience has shown me.

 

[pellicle]

Gail

you didn't ask me, but ..

Are you comfortable getting strips from an unknown source? I ordered Coaguchek XS strips from e-bay and used all 48 with seemingly no problems.
But, when I mentioned to Alere that I got them off e-bay, she wanted to tell her supervisor, and sort of made me worried about it, darn it! So, I got my last order from Alere.
Are you all comfortable with your source for strips?

I have seen some on fleBay which suggest that only the packaging is damaged, they have photographs and you have to buy the 'slab' of bottles. I can see why they would not be commercially sellable and in those situations I would feel comfortable.

however here in Australia I can get them for not much different to those prices. So its not worth my while (postage included).

 

[pellicle]

further to why one should weekly test, I seem to have had a few 'fluctuations' in my responce to warfarin over the course of the month. This represents weekly data ... it started out (in this sample) at day 1 with my INR being right on my low boundary, so I increased my dose each time by small increments.

Prior to this chart my INR was 2.4 and I was just ticking along fine at 7mg a day. Then I noticed it fell to 2.2 ... I thought I'd leave it another week and see where it went to, so since it was still on 2.2 I thought I'd up my dose to 7.3mg a day.

it got to 2.5 which I thought was Ok, but thought I'd just see what happened with changing that to 7.5mg a day. It rose to 2.8 which I thought was higher than it should have gone to. So I dropped my dose back to 7.3 and then it fell during the intervening week back to 2.2

I found this curious as my daily dose before had been more like 7 to give me an INR of 2.4 So I decided to intervene by taking an extra 2mg (that's a total of 9mg) that night and going back to the 7.5 mg dose and measuring again 4 days after (why not?). That puts me at today. My INR now is at 2.8 as at this morning measurement, I will remain on 7.5 and will be interested to see what Saturday brings.

Historically I should need only 7mg daily, but I will wait to see Saturdays result and work from there. If my INR remains under 3 I'll remain on my dose, if its gone up I'll reduce it, if its gone down I'll be scratching my head and wondering.

I do not know what would have happened had I just kept at 7.3? Would it have remained at 2.2? Would it have kept dropping? I don't know.

So I will measure again on Saturday (my normal day) and see what my INR is then.

Normally I measure once a week, but only bother with this sort of frequent measurement of stuff if my INR fluctuates too much. I can think of no reason why such fluctuation would occur, as I have not suddenly eaten a carton of spinach.

So, if I was measuring monthly what could have happened? Could I have gone high and/or low??

I'm not bothered by this, its only a few moments out of my day. But I post this here so that others can see that its not always the case the INR is stable even for people whom its often stable for ...

 

[Protimenow]

Your chart shows that INR doesn't always remain stable, even for those of us for whom the monthly 'snapshot' stays the same.

There's one thing that comes to mind -- and it may be related as much to the meters as it does to your actual INR.

The CoaguChek XS (which I seem to recall that you are using) and the InRatio take a measurement of capacitance to determine when a clot forms (rather than actually detecting a physical clot). The results could change, based on your Hematocrit or Hemoglobin values. For those who have seen some of my other posts, you'll probably remember that I'm testing with the Coag-Sense (which detects the actual clot and isn't sensitive to Hematocrit or Hemoglobin values) and with the CoaguChek XS (and occasionally with the InRatio and the ProTime meters). My INR, as reported by the Coag-Sense has always been lower than the result from the InRatio or the CoaguChek XS. This caused me to wonder about my HCt and HGB levels--are they, perhaps, causing the CoaguChek XS and the InRatio to report higher than the Coag-Sense?

In your case, I wonder if the fluctuation was originally related to your HCt or HGB, or if there was an actual change in your INR. (Speaking only for myself, based on test results, if I had a doctor, and an affordable lab, I'd get these blood factors tested so that I can get a sense of whether or not the 'H and H' are an issue).

 

[Protimenow]

Gail

you didn't ask me, but ..



I have seen some on fleBay which suggest that only the packaging is damaged, they have photographs and you have to buy the 'slab' of bottles. I can see why they would not be commercially sellable and in those situations I would feel comfortable.

however here in Australia I can get them for not much different to those prices. So its not worth my while (postage included).

Interestingly I actually bought the 'slab' of CoaguChek XS strips that Pellicle mentions. The 'slab' was 10 boxes of 6 strips. The group of bottles were all held together in a plastic wrapper. The boxes that the bottles came in had a defect in the small round piece of plastic that sealed the box. The 'slab' came from a seller who is located in the same city in the United States where Roche has its headquarters. I have used the strips. Those that I've used have all passed the internal quality control testing when a test is run. I'm comfortable using the strips from this 'slab.' In order to save a bit of space, I've combined a few of the boxes into bottles of 24 strips. If the temperature here goes much higher than 90 degrees, I may pop them in the refrigerator or in an insulated bag to keep them away from too much heat.

I've had good success with my strip purchases on eBay.

 

[pellicle]

In your case, I wonder if the fluctuation was originally related to your HCt or HGB, or if there was an actual change in your INR. (Speaking only for myself, based on test results, if I had a doctor, and an affordable lab, I'd get these blood factors tested so that I can get a sense of whether or not the 'H and H' are an issue).

I can only say that when I was lab testing that they were forever adjusting my dose and asking me to submit for testing adain next week

I am seeing that like so many other things this has some natural harmonics

 

[tom in MO]

Part of my work is in drug development and manufacturing. I would not recommend buying anything that has not passed the full quality control check and been released. The boxes you got may have had a defect in only the seal, but this defect may have meant the product was rejected before full release. Some final testing may not have been done.

In addition, since the product was rejected and you did not receive it from an authorized supplier you have no assurance it was stored propely. Strips need to be stored properly to maintain the effectiveness.

Finally, the stability of the strips is tested in the exact product configuration of 6 strips to one bottle in one sealed box. Opening the boxes and combining the strips may seem like good sense, but you have no assurance that the expiration date is still legitimate. For example if the product is senstive to moisture, then only 6 exposures to high humidity would have been tested, not the 24 exposures you will now be having. My strips, Coagucheck XS, state they are sensitive to the environment and not to open the container for more than some set time period.

Buy your drugs, testing supplies and test machines only from legitimate distrubutors.

 

[Protimenow]

The CoaguChek XS strips are often sold in tubes of 24, or two tubes of 24 each. Combining the 6 strip tubes into 24 strip tubes was replicating what the manufacturer probably also does. These were all from the same lot, and exposure was for a few seconds. If I recall, the XS strips are okay if exposed for less than ten minutes.

I have bought my supplies from medical supply companies, and also from the manufacturer. The only time I had a problem was when I bought some ProTime strips from a medical distributor...these strips had a problem that I reported to the manufacturer...and these were recalled. The advantage, in this case, of buying from a licensed distributor is that they had information about my order and were able to contact me with recall information.

 

[Protimenow]

Tom:

I've read and re-read and re-read your posting. At first, it sounded like it was written by a person who worked for one of the drug manufacturers, protecting the company's interests.

If it weren't for the fact that the results of these strips were very close to the results of the InRatio strips, I may have been a bit more suspicious of these strips. But having TWO different meters giving me approximately equivalent results any time that the tests were compared, made me think that both were doing tests that were as accurate as the particular testing method allowed.

I'm seeing now that it may be possible that the strips that I bought for the XS did, at some point, perhaps not go through final testing (although it is rather hard to believe that they would have been packaged, sealed, and wrapped for retail sale if they hadn't.) It's also a bit hard to understand how these strips would have made it into the hands of another seller, rather than just discarded. (Of course, it is also possible - though probably not likely - that a Roche employee removed them from the trash before they were destroyed).

My blood work was okay, so this shouldn't have resulted in testing errors by the XS strips. If I can, I'll run a test and compare it to a friend's meter and his strip and see if they agree.

 

[tom in MO]

A manufacturer can only test the variables for which they have the money and time. It is the "religion" of Good Manufacturing Practices, to find the right way and execute it the same way every time. The right way is "validated" to make sure it will work. Any step outside of the "right way" is untested and the product, machine, implant will be rejected. It may still be good, but the manufacturer cannot prove it, thus by law it must be rejected. A change must be validated before it reaches the patient. Any change in packaging, storage, etc. has not been validated and thus the effect is not known.

Often this does not make sense to the people. How can something be good today, but not in a week past its expiration date? It probably is good, but the manufacturer has not tested it, thus they must reject it. We as consumers can take risks, but when it comes to a complex system like the INR machine and its strips, with the risk being potential stroke or death...the stakes are higher.

For example, this week I had a fungal problem in a warm moist area. I used some miconozole nitrate powder that is 4 years past its expiration date. It worked fine. However, I am a chemist who works in the field, and I knew it would not hurt me. However, I had a wee bit of trepidation. Not that it would hurt me, but that it would not be effective. Luckily it was and I don't have to buy more.

Now I use tiger balm for aches and pains. It has an expiration date because some of the chemicals are volitile. It stops working as good as it can before the expiration date. I throw it away when it no longer works, not by the expiration date.

There are many anecdotal stories about small changes in processes or storage that made big changes in products. This leads to people being very cautious in the drug and medical device field. One example are replacement hips. One brand used to have an acid cleaning step. Someone dropped the acid cleaning because it was not really needed; the other cleaning steps removed all residual oils, dirt, etc. This change was validated intellectually and in the laboratory. Afterward there was a significant up-tick in hip replacement rejections. It turned out the acid cleaning was not needed to make the hip clean, but it was removing some trace metals in the surface of the prosthesis that some people are sensitive to. This effect could only be assessed in the patient not in the laboratory. If they had never tried to change the process (to save money and time) there would not be several patients that had two instead of one hip replacement.

 

[pellicle]

If they had never tried to change the process (to save money and time) there would not be several patients that had two instead of one hip replacement.

I'm impressed that they actually did the work to trace it back to that!

I would be pissed off if I was one of those 'multiple operation' patients, that's for sure!