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CWD Meets CGM.

"The problems are that they aren't accurate all the time and they don't replace fingersticks."  She adjusted her shirt collar.  "It's tough for insurance companies to get on board with that."

It's no surprise that I attended every CGM focus group offered at CWD.  From discussions about government viewpoints with Arleen Pinkus of the FDA to debates about accuracy with Dr. Bruce Buckingham, I was tuned in and looking for ammo against my insurance company's repeated denials.  (Acknowledgment of my second appeal arrived in the mail while I was away.) 

When the group (which included Manny, Sara, and the man himself - Bennet) asked about insurance coverage, the FDA lady told us that there just wasn't enough data from the Medicare crowd.  

"So you're telling us that we just need to slap a few sensors on some 65 plus diabetics and that will help turn the tide?" I asked.

She actually said, "Yes.  That would do it."

Fight for your right to monitor!

Fortunately, the CGM session with Bruce Buckingham was far more informative and armed me with enough information for my third appeal letter.  He was a warm and soft-spoken man who lead a 90 minute session about CGMs and how they can benefit the life of someone with diabetes. 

"When I worked at the diabetes camps, they called me a pancreas, because my pancreas worked," he quipped to us, talking about the history of diabetes and explaining how physicians used to taste the urine of their patients to make a diagnosis.  "The first pump was in 1978.  The first common place meter was in 1980.  I know - the pump was before the meter!"  

Dr. Buckingham talked about how CGMs don't measure blood glucose, but instead measure the interstitial fluid.  He told us that it takes about six minutes for the blood glucose to affect the interstitial fluid measurements, which helps explain how CGMs and glucose meters don't always match up with precision.  He cited that the delay is more realistically a full eight minutes.

There was a lot of discussion about accuracy.  From my almost 22 years of experience with type 1 diabetes, I'm convinced that every mg/dl result is a concrete one.  It's been a tough mental hurdle, leaping from snapshots to trending.  But Dr. Buckingham confirmed yet again that a CGM is a trending, and not a treatment, device.  Any CGM result should be confirmed on a glucose meter before treating with food or insulin. 

Another point he touched upon was that of sensor calibration.  I test upwards of 15 times per day, so I was inclined to calibrate my sensor whenever I tested my blood sugar.  "Calibrating when unsteady can cause the sensor to be biased," Dr. Buckingham said.  If I test and my numbers are rapidly rising, I'm calibrating my sensor on the climb.  That's going to throw off the accuracy for sure.  Calibrating when steady (or at least steady-ish ... diabetes is never completely precise) helps retain the integrity of the sensor.  But there is always a lag time with subcutaneous sensors, i.e. recovery from a low blood sugar may not be apparent on a sensor in a timely fashion.

All these technical details were well and good, but I wanted information on what made someone a good candidate for a CGM (particularly in the eyes of insurance companies).  Dr. Buckingham provided a list of possible candidates:

  • patients at a high A1c
  • patients with a fear of hypoglycemia
  • hypoglycemic unawareness
  • pregnancy/preconception
  • gastroparesis
  • athletes
  • patients on medications like pramlintide (Symlin) and exenatide
  • patients who may wear the sensor intermittently to better understand their own diabetes

I saw myself on that list several times.  Dr. Buckingham told the group about how a CGM can provide fantastic feedback that can really affect diabetes management decisions.  He said that the immediacy of the feedback helps identify causality, meaning that we could see how different foods affect blood glucose levels, and that the data can be use to prevent or detect earlier extremes in glucose levels. 

He did have some warnings, though.  He warned about over-calibrating (as discussed before).  He also warned against insulin stacking (taking small bolus after small bolus in efforts to correct highs). He also acknowledged that some of the alarms weren't effective, and that many PWDs slept through them.  One tip he offered was to keep the CGM receiver in a glass on the bedside table, so that when it vibrates, the rattle in the glass helps wake you up.

"It doesn't work unless you wear it," he offered, adding that the sensor is a behavior modification tool and if you aren't ready to accept diabetes, you may not be ready to wear an extra device.  According to Dr. Buckingham, a CGM can make someone feel vulnerable and defensive, with every number out there on display.   

But then he said this:  "A CGM can help you achieve a better A1C without increasing hypoglycemia."  I thought about the lack of lows I've had in the past few months, and I was happy to not be crashing and burning in the middle of the night.  But an elevated A1C also came along without those lows to tip the curve.  I'm so hopeful that a CGM will help me gain better control of my diabetes without tossing my numbers down the well every few days.  

I thought about how Chris said he feels safer when I wear it.  My mom said the same thing.  And I agree.

Come on, Insurance Companies.  Get on board!!

Editor's Note:  Do you want to join the fight for CGM coverage?  Sign the CGM Denial Petition and Raise Your Voice!! Also, Dr. Bruce Buckingham is leading a chat about Continuous Glucose Monitors on DiabetesTalkFest tonight.  Log in at 9 pm EST!

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Kerri, this is an excellent summary of the issues. We've been having an energetic debate about CGMS on Diabetes Daily over the last few weeks. Based on that, there is one critical topic I would add to the list.

Sometimes a censor simply doesn't work. From beginning to end, it is all over the place. It can be inserted at the exact same angle, 1cm from the last one that was working, and deliver results that are off by 200 points and never trend towards the right numbers.

This happens 15% of the time with Elizabeth. Does that mean that the CGMS isn't worthwhile? No. But there can be an enormous frustration factor, especially if your expectations are out of tune with reality.

Wow! Great post! So much cool info! (Especially the old school docs who had to taste the urine?!?! Gross!)

I am on Medicare/Medicaid and I am getting ready to but the CGMS from Medtronic out of pocket due to a law suit settlement, so I could send information to Medicare to help fight with insurance.

I applaud you heartily for going forward in your quest for the CGMS. I was going to start that battle back in Feb. and had the paperwork from my dr. (although they cautioned me that I am "too healthy." ??? Three major hypo episodes? Full-time caretaker of a small child? Are these not good reasons for a CGMS?) I decided to wait when my insurance started creating issues about paying for normal prescriptions. Then I thought about the fact that I don't usually hear my pump alarms (Paradigm 722) when I'm sleeping and the Minimed CGMS uses those and I don't really want another device to keep track of... Oy.

I think my family would have more peace of mind if I had one. We just can't afford to pay for it out-of-pocket. This insurance stupidity reminds me of their nonsense about covering birth control. Refuse to pay $30 a month for the pill BUT they'll pay 100% (something like $30,000) for a pregnancy and birth. What? Who really is deciding these things?

Kerri, sounds like a great session. I’ve been using CGMS for 18months and wouldn’t swap it for the world, but I’d agree it has lots of quirks you need to be aware of. Picking up on a couple of the points you mentioned:

Accuracy - bear in mind that your meter isn't 100% accurate, we only accept their results without question because we have nothing to compare them against. One of the problems with using CGMS is that you have two versions of the truth and you need to understand where each of them is coming from.

Knowing when to trust it - CGMS can't keep up with fast changes, I find it loses accuracy if I’m rising or falling very quickly - the sensor can't keep up with the rapidly changing BG levels. For example, if I see that I'm 10 (180) and rising really fast, I'll always do a finger prick because it's likely that I'm really around 14 (250) and the sensor is lagging behind. Without the CGMS I wouldn't have known I was rising in the first place, it alerts me to the need to do a blood test and check.

It doesn’t replace finger sticks, but I think it does reduce them - I used to do around 6 tests a day. With CGMS I do 3-4 max. I tend to use 3 of them to calibrate the CGMS and only do others if I'm rising or falling rapidly.

On the rare occasion I don’t wear the CGMS I find it really weird to do a test and see that I’m 4 (72) but have no clue of the trend. If I was wearing the CGMS I’d know whether I was falling and needed food or whether I’d actually been 4 (72) for the last hour and I’m pretty steady. The spot test seems like only half the story without the trend data.

All in all, I wouldn’t swap it for the world and it helped me get my A1c down from 6.7 to 5.4 without excessive hypos. Good luck with the appeal, keep the pressure on.

I have been using CGM from Medtronic for about 4-5 months now. I love it!! If you upload your data to Carelink the reports that can be generated are fabulous. The trending graph is what helps me the most. I will look at an entire week to see if I have any patterns both good and bad. I used have highs at dinner time that trended upward til 3am. Well I showed that to my Endo and we began tweaking my basal. Now my BG is in the green zone most of the time.
As far as accuracy if you look at your results over a long period of time they are very accurate and as you mentioned they are not as accurate at an exact moment. That is ok! Trending is where it is at and will help most people with their BG management a lot.

re: this comment-
"Then I thought about the fact that I don't usually hear my pump alarms (Paradigm 722) when I'm sleeping and the Minimed CGMS uses those"
I wear the MiniMed Paradigm 522 with CGM. While I agree that their alarms (high-pitched and not very loud) are difficult to hear, I simply set my pump to VIBRATE in order to alert me to high and low BG's. It works really well, and I never fail to awaken when it vibrates!!!!!

I'm just beginning the fight with my insurance company after being denied.

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