28 Responses

  1. tmana
    tmana July 22, 2014 at 4:58 am | | Reply

    As a person with Type 2, I’d certainly like to “borrow” a CGM for a week or so in order to see where my highs and lows are, what foods might be “trigger” foods (for which I’d need real-time information), what my normal patterns are. I believe this sort of information is essential when looking at appropriate therapy (exchange, low-carb, paleo, or other diet type? prandial or background oral medication? etc.) for Type 2.
    As an e-patient, I’d rather have access to my data in real-time — but for someone who doesn’t have the personal interest or incentive in following the data and doing even MORE real-time logging of even MORE stuff, a “blind” study (especially at the point of initial diagnosis) may be indicated.

  2. Joe
    Joe July 22, 2014 at 5:11 am | | Reply

    This whole thing pisses me off. Why don’t most of these so called Endo’s want their patients to see the data off of a CGM? I’m a T2 who has a Dexcom G4 CGM, that I consider a godsend. It lets me know when I get to low. Before the CGM I was low unaware until my blood sugar dropped to 47.

  3. Brian (bsc)
    Brian (bsc) July 22, 2014 at 5:27 am | | Reply

    Unfortunately I think some of the subtleties about why a professional CGM makes sense have been lost. I think there are two major reasons for a professional to employ a CGM with a patient; the first is as a trial for the patient to see how a CGM may be able to benefit the patient. The primary user of the CGM is that patient and obviously it should not be blinded.
    However the second use is to observe the patient blood sugars without impacting their current management regime. And in this case the use of an unblinded CGM can seriously obscure things, disrupting efforts to characterize the patient and destroying research. Think about it, you have a patient, they binge eat and have poor blood sugar control. You pop a CGM on them (sorry for the technical term) and observe them for a week. The patient sees their blood sugar and “changes their behavior” during the observation period. At the end of the week the doctor has nothing. Absolutely nothing. If you let the CGM be seen by the patient it can change the behavior totally negating any value.
    That being said, I am deeply offended by the suggestion that patients shouldn’t be allowed to see CGM results because they won’t use that information. Doctors that don’t empower their patients from the beginning are not being effective. That is the same myopic view that is used to justify T2s not testing their blood sugar. If you just bring a log of your readings to your doctor, that is useless. But if you test and change your behavior, that is invaluable. So I ask people like James Thrasher and Fran Kaufman to remember that our first line of defense against high blood sugars is the patients themselves and that if we just bothered to educate them to change their behavior based on the information they obtain from their glucose meters and CGMs it could be a different world. This goes for T1s and T2s.

    1. Becky
      Becky July 24, 2014 at 1:14 pm | | Reply

      One key thing in your statement, though, is the fact that they were able to make a change in their behavior to modify their results. The clinician would now have proof that the person could change, and this could be an excellent teaching tool! As a patient and a clinician both, I think this is the real value that I see from working with my patients and myself. If we can se our data, we can make changes. I guess if you need blinded data for research, that is a different situation.

    2. God
      God August 8, 2014 at 10:37 am | | Reply

      This is an interesting debate that I am sorry that I am late to.

      First, the benefits of blinded CGM are unbiased data and efficiency for the clinic. Unbiased data is the key. Not everyone will get nor use CGM – type 1 or type 2. The adjustments made on a blinded/unbiased CGM device means the HCP can have more reliable information and make more meaningful therapy decisions that should have a longer term impact. Further, by keeping the logs HCP’s/dieticians can then show it to them afterwards and have a much more meaningful consult. The efficiency part of it is a real thing that doctors have weigh since their offices are so busy. The G4P is a very simple device, but there should be some training (CGM success depends heavily on initial training) – we may be smart and used to our CGMs here, but others aren’t that lucky.. What happens if I get this alarm – WHO do I call (probably the doctor’s office)? Blinded CGM is much quicker to start a patient on. As we all know doctor offices are busy and must make trade-offs.

      Anyone using blinded CGM as a trial for real-time CGM is an idiot.

      The chance of someone dying while wearing a blinded CGM is probably pretty low (given this is the only one we have heard of and given the probably 10′s of thousands of patient years it has been worn). In this patient’s case he was having trouble with nocturnal hypo’s – an issue he had for much of his life with diabetes. If they put him on real-time he may make adjustments before bed that alter the results and they don’t find out what is happening (remember, labeling back then wasn’t for more than 3 days). Speaking of back then, at this point reimbursement for CGM was still rather pathetic so real-time may not have been an option (the article was submitted in july 2009 – it probably occurred at least 6 months if not a year before that which would mean reimbursement was even worse!). This is not to take away from his death. One death is one too many and I believe everyone with diabetes should be on CGM, but this isn’t reality.

      If someone isn’t a candidate for real-time CGM (most type 2′s, still many type1′s) a doctor may only have blinded CGM their option. With CGM being so available now and having better reimbursement it is being used more and more proactively instead of as a last ditch effort as I feel this guy’s case was. Should there be an alarm if the BG goes below 40? Absolutely.

      To me this is fear-mongering. I don’t even know why this is a debate. ADA and AACE both support blinded CGM, very clearly at that. Sure, the CMO of ADA disagrees, but based on his statement he doesn’t fully understand professional CGM given that he shows no understanding of the reporting process. Fran Kaufman doesn’t talk about safety? It is because the device is safe. Does it add safety? No, but of one potentially preventable death in what is probably thousands if not 10′s of thousands of patient years (assumption: 15k patients per year x 6 years x 4.5 day (average of 3 and 6 day wear)/365 – I have no idea how good of an assumption this is). Yes, this assumes we hear about all instances, but I’m sure we would somehow – probably from this website)

      There is a zeitgeist in the diabetes community about data. I love data as much as the next person and more should be done with it and made available, but this question on this topic is misplaced. Finally the fact that Dexcom has made their device blindable should be another sign that this is going away. The value for Dexcom, of course, is that they only have to sell a doctor one device and he gets both funcitonalities. Chances are, if a doctor wants a patient on real-time CGM, they will just prescribe it.

      Sorry for the rant.

  4. MikeH
    MikeH July 22, 2014 at 6:11 am | | Reply

    Thanks for the great post, Wil! I tend to agree that blind CGMs can serve a purpose for those wanting to “trial-test” this kind of device or for those who simply don’t have the desire to track all of this data themselves. But to Brian’s post — I’m not sure I completely agree about real-time access to data changing behavior and skewing results; actually, I think I see it the other way. Most of the time, as I’m gearing up for endo visits or even clinical trials, I find myself changing my behavior and “doing better” just because I’m going in to see the doc. I did this even as a kid — not logging my blood sugars until the day before, when it looked like I was doing it the whole time, and then a few days in advance of the appointment, following my meal plan and doing everything the way I should’ve been. I get a more “real-time view” of my data by simply living, when the doc isn’t involved and I know I’m being watched. Even if you can’t see your data on a blind CGM, you’re still obviously under the doctor’s eye and all that data will be reviewed after-the-fact. So, with that in mind, I see it differently. And on top of what you’ve reported, that’s even more reason I think real-time is the answer if someone’s able and willing.

    1. Ben
      Ben July 25, 2014 at 7:49 am | | Reply

      Mike your point is spot on. This is one of a few points I wanted to make, and I’m glad you said it. Dr. Thrasher is naive if he thinks patients behavior isn’t affected or altered by having the CGM recording, blind or not. I’d compare it to having a GPS in your car that transmits your speed to the nearest police car….of course you’re not going to go above the speed limit.

      Moving on, I feel like, as Wil alluded to, this discussion is just a paradigm for a bigger discussion that is also taking place. For adult patients, are endos/educators/NPs/dietitians/etc in control or is the patient in control? Shouldn’t the medical D-team’s goal be to hand control over to the patient? Not just bolusing for a meal, but basal rates, bolus I:C ratios, testing times, diet & meal size, exercise, etc should all fall into the patient’s control. Not because the medical d-team can’t do it, but because it is a fluid disease with ever shifting requirements and needs. It just seems that patients are in a much better situation to know what is needed in any given situation after a while than a doctor they see once, what, every 3 months. Sadly, it sounds like Drs Thrasher and Kauffman disagree and think only doctors can interpret and analyze BS readings and decide what needs to be done. That’s…a slap in the face, in my opinion.

      Lastly, saying a blind CGM is great because it is more convenient and easy is ridiculous; both in what the reward is (saved time for the doctor, nothing for the patient) and what it implies (patients can’t figure out how to use/sync a CGM).

      I don’t see how anyone can make a case for a ‘blind’ CGM without coming off as condescending, arrogant, and, frankly, a terrible doctor or at least one with archaic views as Dr. Ratner mentions.

  5. Kathy
    Kathy July 22, 2014 at 6:31 am | | Reply

    We are not lab rats. If we had perfect insulin and oral meds that always and predictably did what they were prescribed to, and if we lived in controlled environments with scheduled meals and stressors…but no, of course we don’t. So don’t take tools away in the name of “doctor knows best.” Doctors might know medicine but we who live with the monster know our diabetes best.

  6. Mike Ratrie
    Mike Ratrie July 22, 2014 at 7:18 am | | Reply

    I guess there ARE two sides to every story …

    I think Brian has hit it very well in describing the benefits of having a blinded CGM. However, Wil has uncovered a disturbing mindset in today’s 15 minute appointments, 4x per year regime that many diabetics live in.

    What is a bit surprising to me is that the FDA did not ask the blinded CGM manufacturers to build in some sort of alarm to warn the patient in real time of either an extreme low or an extreme high. While this might have a negative impact on the value of a blinded study, it could have a positive impact on CONTINUING the life of the PATIENT.

    Also, as someone who has a CGM, but does not have a Windows OS, let me reiterate the big picture – IT’S OUR DATA!

  7. Paul P.
    Paul P. July 22, 2014 at 7:22 am | | Reply

    You hinted at a problem that effects any kind of medical record. Whose data is it, the doctor’s, the patients, the insurance company, the governments …? It is a matter of personal liberty that as far as I know hasn’t been completely addressed.
    I think that a real time CGM with data viewable to the patient is important to patient safety, particularly if one is using insulin for bg control.

  8. Melinda
    Melinda July 22, 2014 at 7:38 am | | Reply

    Ah, the beauty of the cloud…at some point, patients will get to determine just who has access to their real time data. Just imagine if that young man’s family had CGM in the Cloud. #wearenotwaiting

  9. Betn
    Betn July 22, 2014 at 8:19 am | | Reply

    It seems like Mike’s thought that even the blinded CGMs should be able to alert to extremes should have been already instituted. From Brian’s comments, I can see how in some patients the blinded could be beneficial for getting a baseline – but I think it should then be followed by an unblinded one, to be used to education and for seeing how any discussed changes are working. That it “takes too much education” is a just a symptom of the far larger problem of health education & agency that we have in this country, unfortunately.

  10. Mary Dexter
    Mary Dexter July 22, 2014 at 8:29 am | | Reply

    Blind CGMs should be used only for research studies of non-diabetics to determine how a ‘normal’ person’s blood sugar fluctuates or in cases where the receiver is a few feet away in the hands of a person standing ready to resuscitate the patient.

    The diabetic community should be angry. Dr. Thrasher’s attitude is especially galling. He describes his patients as mostly uncontrolled, but fears they might change their behavior. People who want it to be “all about them” shouldn’t go into medicine.

  11. Bob Fenton
    Bob Fenton July 22, 2014 at 9:51 am | | Reply

    Having used one myself, I agree it is my data and I did not like that I could not see the data until after the data was downloaded. My trial was for three days only, but clearly showed that under current guidelines, I was not eligible for a CGM. Of course I knew this because Medicare will not authorize this. One of the disadvantages of being over 65.

    This is one thing very few people even discuss and whether you are type 1, type 2, or any other type, once you are on Medicare, the cost is all yours.

    i learned some valuable insights from the three days, after the fact and comparing the readings and graphs to my data, but still it would have been a lot more valuable to have seen the results as they happened and to have known immediately.

  12. Tim Steinert
    Tim Steinert July 22, 2014 at 10:24 am | | Reply

    If I were being given a sleep study in a clinic, would they keep doing the test when I haven’t breathed for a minute? Or would they stop the test and treat the patient? A patient at home deserves the same consideration. The idea that a “professional” CGM cannot both record information and warn its wearer of imminent danger makes me want an “amateur” one.

    1. Brian (bsc)
      Brian (bsc) July 22, 2014 at 4:14 pm | | Reply

      I suffer from sleep apnea and at my first sleep study I stopped breathing for 180 seconds. That is three minutes. They didn’t stop the test even though later evaluation showed that my oxygen levels had dropped way too low. I believe the general thinking was that this was a “typical” night. If I didn’t wake up, I think they would have considered that just the luck of the draw considering that I was taking that same risk every night.

      Three minutes. I can’t even do that holding my breath in the pool. Can you?

  13. Scott E
    Scott E July 22, 2014 at 1:48 pm | | Reply

    I used the Medtronic ‘Blind’ CGM for about a week – this was a few years before I started regularly CGMing. While it drove me nuts not having access to the data, I can see the benefit.

    I recorded my BG’s manually, and the CDE who had me on the CGM was able to “retroactively” calibrate it with the BG’s I gave her, picking and choosing the best ones (i.e when BGs were steady). If I had to calibrate myself – and had no idea what I was doing – I probably would’ve calibrated it 10 times a day and grown increasingly frustrated as it never tracked properly. So in that case, I think the blind usage was appropriate.

    For a patient who isn’t ready to learn CGM, but could use some assistance in basal testing, I think the blind usage would also work.

    1. Mary Dexter
      Mary Dexter July 22, 2014 at 3:06 pm | | Reply

      My Dexcom G4 is very easy to calibrate. Most of the time I do the two fingersticks in a row and it’s reading accurately. The Medtronic, on the other hand,….

    2. DaN
      DaN July 23, 2014 at 8:16 pm | | Reply

      It is hard to understand your point. Where is the benefit of being blinded? Calibration?

  14. David
    David July 22, 2014 at 3:05 pm | | Reply

    I want to weigh in on the argument about alleged benefits of blinded cgm use. I think some here are “missing the forest for the trees.”

    E.g., Brian said: ‘The patient sees their blood sugar and “changes their behavior” during the observation period. At the end of the week the doctor has nothing.’

    But, isn’t this actually the best possible outcome for _the patient_?
    Through trial and error, with real time feedback, this patient taught themselves in one week to do something that it might have taken the doctor months to train and convince the patient to do!

    This attitude just sounds like good old-fashioned stubbornness to me. Let’s not lose track of the purpose of healthcare: to enable the patient to live a (maximally) healthy, happy, and productive life.

  15. Tom
    Tom July 22, 2014 at 6:21 pm | | Reply

    Blinded systems should audio alert the user when it senses a low reading, say 55 or 60. No number needs to be displayed which would satisfy the so-called professionals who are terrified if a patient sees a number. Such an audio alert may have saved the life of the young man in the case study Wil described.

  16. RenzaS
    RenzaS July 22, 2014 at 6:34 pm | | Reply

    This is a really thought-provoking post. Thank you!
    My line is always this – if the data is available, I want to see it. It’s my data, I understand it, I can interpret it. For me to get the most out of this very expensive technology (there are no subsidies for CGMS in Australia), then I want access to every bit of information it is providing.

  17. Allison
    Allison July 22, 2014 at 6:46 pm | | Reply

    I have had a CGM since November, and after dealing with type 1 for nearly 20 years, I consider this to be the best thing that’s happened to me in the diabetes realm. It is horrifying that physicians would insist on doing blind studies and not let their patients see their own data.

    My primary care doc wrote the referral for my CGM without a problem. When I went back to my endo, she barely looked at the data but said she has been starting to refer patients for CGMs over the past year. I hope that more physicians come around soon.

  18. Lady Imp
    Lady Imp July 22, 2014 at 7:15 pm | | Reply

    I will admit that I’m torn on the issue. Mike brings up an interesting point, that people will change their routines in anticipation of the doctor’s office regardless of whether or not they are on a CGMS or collecting data, and I find that to be a fairly accurate statement – I did it as a child, and only stopped after I grew up and realised that I would benefit more from being honest with my doctor.

    And now that I’ve said that, I think I have identified the real problem with this: people aren’t honest with their doctors. They are purposely skewing data, purposely correcting their regimen but only for the time required to obtain good chems so that the doctors would be happy and spare them the complication threats. Perhaps what really needs to be done is doctors need to stop threatening people into compliance and instead start leading them to it. Then maybe blind CGMS would become unnecessary.

  19. Daniel
    Daniel July 23, 2014 at 12:07 am | | Reply

    Dr. Robert Ratner is the man. What a wonderful statement of rational thinking and clarity of thought he provides to the subject. I would not step foot in Kaufman or Thrasher’s office.

    One thing about Kaufman, she is just a business women masquerading around as a doctors.

    The rational position that cannot be denied: You put the professional CGM on the patient, you tell them that you want them not to worry about the numbers but eat as you normally would. However, if you blood sugar drops, and/or an alarm sounds, act upon it!!!

    If a doctor cannot treat a patient in such a manner, they have a problem and need to take a walk down to the psychiatric ward.

    Doctors need to advocate for safety and health. How could you argue for another position. And don’t tell me that seeing the numbers will influence behavior. Give me a break. Having the professional CGM connected to a person will have that impact. Don’t you think that person is smart enough to know the doctor is watching?

    Physicians are no longer allowed to be paternalistic,” Ratner says. “It didn’t work 30 years ago, and it doesn’t work today.”

    Ratner rules!

  20. John
    John July 24, 2014 at 6:32 am | | Reply

    Thanks for the great post .Thats correct, blind CGMs serve a purpose for those who want to test for this kind of device or for those who don’t have the desire to track all of this data themselves.

  21. Adam Berger
    Adam Berger July 25, 2014 at 7:55 am | | Reply

    Great post filled with the great analysis, as always.

    As a type I since my senior year of college, I think there’s no question that I own the data generated from my body and it’s my responsibility to analyze it and use it to inform the decisions I make every day. Doctors can help, columns like yours can help, and there are plenty of tools that can help, but at the end of the day, I’m the one who needs to live with diabetes so I’m the one who needs to understand what’s going on in my body. Anyone, doctor, device maker, or otherwise, who discourages patient involvement and ownership of their care is doing a severe disservice to their patients/clients.

    Your articles, promoting self-awareness and guiding the way to self-help do far more good than visiting a doctor once every few months who isn’t teaching you how to live with your condition. The idea that patients need to be tricked into supplying the data the doctor thinks he needs is preposterous–that attitude removes any hope of a real collaboration between the patient and the doctor.

    Kudos to Dr. Ratner: “CGM should be a teaching tool and there’s no reason to withhold information from the patient in these days of shared decision-making.” That’s the attitude that will actually help people.

  22. What We're Reading | Quantified SelfQuantified Self

    [...] Have Professional CGMs Passed Their Prime? by Will Dubois. In our continued exploration of the role of data access in the diabetes community we have run across many interesting stories. Wil’s amazing post here describes how some people with diabetes are never given access to what could be the most important data in their lives. [...]

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