Clinical Rationale for CGM in Diabetes

Dennis P. Scanlon, PhD: I’d like to segue to our second segment and talk about payer coverage for continuous glucose monitoring (CGM). We’ll start with the clinical rationale for CGM as opposed to the old-fashioned way. Bob, there was a study published in the American Journal of Managed Care^® in 2011 that looked at some of the outcomes related to this.

Robert Gabbay, MD, PhD, FACP: What that study did, was, for the first time, quantitated the cost associated with hypoglycemia and a hypoglycemic admission to the hospital. The realization, and what, now, subsequent data has demonstrated, is there are more people admitted to the hospital for hypoglycemia than hyperglycemia, and that’s really a big shift from what traditionally had been the case (or what most people think about). So, that makes one think, “What can you do to prevent hypoglycemia?” And one tool is certainly continuous glucose monitoring—that could alarm a patient when their blood sugar is getting dangerously low. They take an action. They don’t end up losing consciousness, ending up the hospital, and therefore, can save on significant costs and morbidity.

Kenneth Snow, MD, MBA: Just adding on to that, it doesn’t even have to be a full admission. Even in what we would consider to be just a simple emergency room (ER) visit related to hypoglycemia, an ambulance transfer, a stay in the ER, and the evaluation that occurs in the ER can run up quite a bill very quickly for a stay that has a potential to have been prevented.

Dennis P. Scanlon, PhD: Has this made its way into the guidelines yet? There’s still a little bit of controversy around when this should be used. What do the guidelines say?

Kenneth Snow, MD, MBA: There’s clearly evidence that exists about when CGM is successful, where it is proven to be a benefit (particularly in type 1 patients who are willing to use the technology), and it shows benefit both in terms of improving glycemic control and lowering risk of hypoglycemia. Once you get outside of that, causation data becomes very thin. You see observational data where there’s clearly a relationship between hypoglycemia and, as Bob said, if you can give them the message and that prevents the hypoglycemic event, well, then that is optimal. But the question that comes up is, there’s not a lot of data that says that if we take folks who we’re not biased and selected for, and we give them a CGM, will they use that information and change their behavior such that it actually relates and yields a decrease in hypoglycemia? We would all like to think so, and we would all like to hope so. It sure sounds logical, but whether it’s actually true or not is what we’re waiting to see. And that is one of the key factors in driving coverage.

Robert Gabbay, MD, PhD, FACP: That kind of data is starting to accumulate. I think you’re right. The important point is not just giving this advice to somebody, but educating them on how to use it and how to use the information. That’s where it needs to be done right to demonstrate value. If it’s done wrong, you might not see an advantage.

Mary Ann Hodorowicz, RDN, MBA, CDE: I’m so glad you said that, Dr. Gabbay, because that’s where diabetes educators have a role—when the physician interprets the data and records the CPT (Current Procedural Terminology) code for billing it and getting money, then that data comes to us to embed lifestyle changes to control those patterns of hyperglycemia and hypoglycemia. But, in terms of what Dr. Snow said, too, (that type 1 diabetics generally benefit the most because of the blood glucose variability and the peaks and valleys) CMS (the Centers for Medicare & Medicaid Services), Medicare, does cover CGM—now, professional CGM and personal CGM for, also, the type 2 population who are insulin dependent. It’s an adjunct. CGM is actually an adjunct to self-monitoring of blood glucose. And there are strict criteria with CMS for coverage where they have to be testing 4 or 5 times-a-day and be on insulin. But it’s good news that Medicare is starting to cover professional and personal use.

Robert Gabbay, MD, PhD, FACP: It’s fantastic news. At Joslin, we have a large type 1 population. And for them, they reach Medicare age and, now, they have to go off of their continuous glucose monitoring, which is a big problem. But I think you’ll see, in the not-too-distant future, this spreading to more use in the type 2 setting. Based on the kind of evidence of people that are on multi-dose insulin, this population can clearly benefit.

Dennis P. Scanlon, PhD: There have been some studies that have helped in this regard. I believe the DIAMOND study is one of those studies. Could you talk a little bit about that?

Robert Gabbay, MD, PhD, FACP: Sure. The DIAMOND study has been a series of studies, and some of the results have come out. One of the studies just recently looked at comparing the use of continuous glucose monitoring to typical home glucose monitoring, and which would be better in a type 1 population on insulin. There were 2 studies. The DIAMOND study had a 1-point drop in A1C (glycated hemoglobin), and a Swedish study had a .5 drop in A1C. They were designed a little bit differently but, clearly, there was benefit. And that’s also helped to allow CMS, and presumably others, to say, “This doesn’t have to be an adjunct to home glucose monitoring, it can largely replace it.”

Dennis P. Scanlon, PhD: Great. How about the importance of the FDA-expanded indication, or Medicare coverage decision, with Dexcom G5?

Kenneth Snow, MD, MBA: Clearly, from a payer perspective, it is always reassuring when what is being requested to be covered is actually approved by the FDA for that use. We see a lot of requests for off-label use for all sorts of things—some very reasonable and legitimate, others not so. But, once you have that FDA stamp of approval, there’s a significant advantage (not the least of which is it usually means that there’s legitimate scientific evidence that fell behind that decision on the FDA’s part). And that scientific evidence is what supports the use.