Medicare’s decision to extend coverage to continuous glucose monitoring systems should expand use of the technology — and improve glucose control among seniors.
New Medicare rules that extend reimbursement to include continuous glucose monitoring (CGM) systems are already leading to greater use among the senior population of a technology shown to improve glycemic control, and the trend is expected to grow.
“Some patients had been waiting for over two years for these sensors to be covered by Medicare. They are really happy about having access now,” says Grazia Aleppo, MD, associate professor of medicine and director of the Diabetes Education Program at Northwestern University, who has moved quickly to introduce patients to the technology. “We also have many patients who are happy Medicare started covering therapeutic CGM because they had been paying for it out of pocket.”
Older patients may find CGM even more beneficial than younger patients, according to Andrew J. Ahmann, MD, professor of medicine and director of the Harold Schnitzer Diabetes Health Center at Oregon Health and Science University: “Older patients are more at risk for hypoglycemia. They are more likely to have hypoglycemia at the same level of glucose control. They are also more susceptible to damage from hypoglycemia, both in terms of cardiovascular events as well as falls, fractures, and other consequences.”
Aleppo says CGM is a useful tool for managing patients: “When the systems are downloaded, one can see much more clearly the challenges of glucose fluctuations these patients are facing. Mealtime insulin-to-carbohydrate ratios can be adjusted, as well as basal insulin doses and correction factors. We can work with the patient on bedtime glucose levels and show them what can be modified to decrease fluctuations both in the low glycemic range and in the high glycemic range.” The patients who often benefit the most are long-term type 1 diabetes patients with hypoglycemia unawareness, having lost the feeling of the symptoms of low glucose.
“Older patients are more at risk for hypoglycemia. They are more likely to have hypoglycemia at the same level of glucose control. They are also more susceptible to damage from hypoglycemia, both in terms of cardiovascular events as well as falls, fractures, and other consequences.” – Andrew J. Ahmann, MD, professor of medicine; director, Harold Schnitzer Diabetes Health Center, Oregon Health and Science University, Portland
Medicare requires the clinician to provide documentation for patients can qualify for coverage. A patient must inject insulin three or more times a day or have an insulin pump, perform at least four measurements a day with a home blood glucose monitor, and require frequent insulin adjustments based on these measurements. The clinician must also confirm that the patient is capable of using the technology.
And although CGM tends to be associated with type 1 patients, the Medicare rules do not differentiate between diabetes types, as the qualifying factor is insulin dependence.
A key next step is to help the patient choose which of the systems available is the best fit — the Dexcom G5 CGM or the Abbott FreeStyle Libre Flash Glucose Monitoring System.
The Dexcom G5 consists of a small sensor that the patient places under the abdominal skin. It measures interstitial glucose every five minutes and transmits the results in real-time to a receiver. In addition to the readings, the receiver displays trend arrows indicating whether and how quickly a patient’s glucose level is trending up or down. It can be set to sound an alarm at selected levels when glucose goes too high or too low. (The Dexcom G5 can be used with a smart phone, but Medicare currently does not support this use.)
The FreeStyle Libre’s sensor, which is about the size of two stacked quarters, attaches to the upper arm. It makes regular glucose readings that the user accesses with a scanner. The scanner displays the readings and trend arrows, but does not have an alarm to notify the user of an impending glycemic event.
The Dexcom provides real-time CGM, whereas the FreeStyle Libre is generally considered intermittent scanning CGM or “flash glucose monitoring because you have to put a reader device up to the sensor to get a reading,” Ahmann says. In addition, clinicians have more experience with the Dexcom because it has been on the market longer.
The Dexcom G5 requires calibration twice a day by the patient, using fingerstick measurements, whereas the FreeStyle Libre requires no calibration by the user, which may make it a better fit for patients who have difficulty getting blood from their fingers as well as those who simply desire a simpler system.
“Some patients had been waiting for over two years for these sensors to be covered by Medicare. They are really happy about having access now. We also have many patients who are happy Medicare started covering therapeutic CGM because they had been paying for it out of pocket.” – Grazia Aleppo, MD, associate professor of medicine; director, Diabetes Education Program, Northwestern University, Chicago, Ill.
At the end of March, the Food and Drug Administration approved a new Dexcom model — the G6 — that removes this difference by requiring no calibration. It is scheduled to begin shipping in early June, but it has not been approved for coverage by Medicare, and a Dexcom spokesperson could not give an estimate for how long it might take to gain that approval.
Differences in the Two Systems
Aleppo says that the real-time data from the Dexcom and its alerts of impending problems make it particularly suited to patients whose hypoglycemia unawareness might lead them “to manage their fear of hypoglycemia by overeating, taking less insulin, being afraid of exercise, being afraid of driving, and eating unnecessary bedtime snacks to avoid overnight events. Patients sleep better because they know that the alarms can notify them or their companion. For people who have preserved feeling of hypoglycemia, the Freestyle Libre is a great tool — convenient and informative. Scanning the flash reader is painless and can be done several times a day. Some patients prefer to be notified about impending hypo- or hyperglycemia, whereas others do not want to hear the alarms.”
Ahmann agrees that the Dexcom might be preferred by patients who have hypoglycemic episodes: “If you want the most data, you would certainly want the Dexcom platform because it provides more information and has the alarms. The Freestyle Libre is a little simpler for the older patient or others who aren’t as comfortable with the technology.”
For either system, patient training is a key to success. “The majority of the training is done by our certified diabetes educators, who already know the patients well,” Ahmann says. “Our educators go through a formatted approach to teach patients how to use it technically, and then teach them how to use the information to their best benefit.”
Aleppo said that education is a multi-step process, starting with becoming comfortable with the sensor before going on to learning about the arrows and dosing. “We teach patients very slowly. We have to make sure they are comfortable with the information they get. You need to first make sure they understand what the alert means, what the up and down arrows mean. Then you can talk about adjusting the insulin dose based on the trend arrows before a meal.”
Ahmann said that the DIaMonD study demonstrated that CGM improves glycemic control in patients with type 1 diabetes regardless of age: “There was no difference in benefit whether they were younger or older. The DIaMonD trial showed not only that age didn’t make a difference, but neither did level of education or ability in mathematics. That study convinced us that this can be effective therapy for older patients, and some of the limitations that we might assume probably don’t exist. But you still need somebody who is going to embrace it. There are certainly some older patients who are averse to technology.”
Both Aleppo and Ahmann say that one of the weaknesses of the Medicare approval is that it does not allow the use of the Dexcom mobile phone app, which can be particularly useful in the older population who have some cognitive decline and may need the help of family members to foresee and manage glycemic events. Both are hopeful that this rule may be revised in the near future.
— Seaborg is a freelance writer based in Charlottesville, Va., and a frequent Endocrine News contributor. He wrote about the threats of immunotherapy on the endocrine system in the April issue.