Understanding Correlates of CGM Uptake, with Lindsay Mayberry, PhD

Lindsay Mayberry, PhD

The prospect of continuous glucose monitoring (CGM) has gone from science fiction to reality in less than a lifetime. Now, the role of CGMs in diabetes management is more pronounced than ever, but questions remain around characteristics that make patients more likely to uptake and adhere to CGM use.

At the American Diabetes Association (ADA) 82nd Scientific Sessions, discussions and symposiums put CGM use under a microscope to better understand and optimize use, particularly in the primary care setting. A pair of posters presented at the conference by Lindsay Mayberry, PhD, associate professor of Medicine and Bioinformatics at Vanderbilt University Medical Center, examined contemporary trends in CGM uptake among adults with type 2 diabetes in primary care or endocrinology clinics within their health system and further explore what patient characteristics were associated with increased likelihood of uptake in primary care.

Results of the studies demonstrated CGM uptake had increased rapidly during the COVID-19 pandemic, with an average of 110.2 patients per month receiving a newly prescribed CGM in 2021. Results of this study suggest associated younger age, insulin use, and higher A1c, but not gender, race, or ethnicity, which is contradictory to the conclusions of many previous studies. When assessing correlates associated with CGM uptake in primary care, the study’s results indicated uptake was more common among patients who were younger (55 [IQR, 47-62] vs. 60 [IQR, 53-68]; p=.031), had higher baseline A1c (9.1% [IQR, 8.1-10.4] vs. 8.3% [IQR, 7.5-9.5]; P=.048), were using insulin (69% vs. 36%, P=.002), and had higher baseline diabetes distress (45 [IQR, 25-55] vs 30 [IQR, 15-50]; P=.09). Similarly to the first study, there were no associations between gender, diabetes duration, race, ethnicity, and health literacy with increased uptake.

For more on the results of these studies and how they can inform efforts to optimize uptake of CGM, Endocrinology Network sat down with Mayberry at ADA 2022 and that conversation can be found below.

Optimizing CGM Uptake with Lindsay Mayberry, PhD

Endocrinology Network: Can you describe the onus behind these studies and what your most significant findings were?

Mayberry: I am a behavioral scientist. So, I design and test interventions to help people with lifestyle change for chronic conditions like diabetes. One of the areas I work most in is type 2 diabetes. What we've observed with our most recent intervention trial is that people are using CGM in numbers we've never seen before. I became really interested in how we need to respond to that, because that's behavioral, right?

It's a health behavior to use a CGM effectively. So, then, it becomes how do we understand what's happening here. One of the things I did to wrap my head around that was look at the incidence of CGM use among people with type 2 diabetes across our health system.

So, we use electronic health record data and we use a prevalidated algorithm to identify everybody that had type 2 diabetes that had been seen in primary care or endocrinology clinics. We said, "Okay, so for this is our patient population or cohort, let's look back for them and see have they ever used a CGM? If so, when did that happen?

What was really interesting is that we found that increased CGM uptake started showing up for these patients in spring of 2018. Then, just like rapidly increased to the point that in 2021, the average rate of sort of new users of CGM was 110 patients a month. That's a lot of people with type 2 diabetes that are using CGM.

So, then we were interested in what characterizes people who are using it versus those who aren't. Using electronic health record data, we looked at demographic characteristics, insurance status, HbA1c, HbA1c at the time that they were prescribed, and race/ethnicity.

Basically, what we found is that the people that were using CGM were younger and they were more likely to be using insulin, but there was a pretty good proportion of them that weren't using insulin at all, which was sort of surprising. And we did not see any differences by race, ethnicity, or insurance status. And that was exciting because there's not maybe a dis unequal distribution, at least within our system of that technology, by race or by insurance status.

Endocrinology Network: Is it encouraging to see that race and insurance type and gender weren't really impacting the rate of uptake or are you concerned this might not be reflective of experiences outside of your health system?

Mayberry: I think both of those things are true. I think it's really great that in our medical center, we're not seeing disparities, I think that's excellent. Our medical center is certainly not representative of what we would see at community health centers. So, to presume that because we're not seeing disparities means there aren't any would be not true.

I'm sure that there are some disparities, but it's maybe happening based on where people are seeking care and insurance probably plays a role, but, at least in our health system, it wasn't, but maybe there weren't as many people who were underinsured in our health system as maybe would be elsewhere. I know that insurance plays a role and CGM uptake. So, I don't want to act like that's not a factor, but it was in encouraging that maybe it's not as much of a factor as we maybe would have assumed that it was.