Causes and Consequences of Continuous Glucose Monitor “Breaks”: Perspectives from Adolescents with Type 1 Diabetes

To the Editor,

Diabetes technologies have changed substantially over the past 20 years, allowing for near real-time monitoring of glucose levels and automated insulin delivery,¹ improving time in range and decreasing hypoglycemia for many people living with type 1 diabetes (T1D).² Yet, adolescents have not achieved the same benefits of these technologies as compared with adults or younger children.^3,4 Increasingly, continuous glucose monitors (CGMs) are being integrated with insulin pumps allowing for automated insulin delivery (AID) with demonstrated improvements in HbA1c and time in range.² However, these devices can only adjust insulin delivery when a CGM is actively transmitting data. Understanding adolescents’ unique barriers to wearing current CGMs and reasons why they may take time off CGMs (what we refer to as a “CGM break”) is critical to improving the care of adolescents with T1D. The purpose of this qualitative study was to explore causes and consequences of CGM breaks in adolescents with T1D.

Participants in a multi-site trial of a positive psychology intervention in adolescents with T1D (NCT03845465) were invited to participate in this qualitative study if they were between the ages of 13–17 years at the time of enrollment and had ever used a CGM. Adolescent participants and their caregivers gave informed consent/assent to participate in this ancillary study which was approved by the Vanderbilt Institutional Review Board (IRB #191245).

Interviews were conducted with 21 adolescents (M_age: 16.6 ± 1.3, 43% female, M_{duration of diabetes}: 7.9 ± 3.7 years, M_{A1c at enrollment}: 8.7% ± 1.2%, 71% White, 24% Black, 5% Asian, with 19% of participants living in rural communities) with T1D who were currently using (90%) or had previously used a CGM (10%). Our multidisciplinary team (consisting of a pediatric endocrinologist, pediatric psychologist, and qualitative research expert) developed an interview guide that included open-ended questions related to the following: (1) diabetes management; (2) decision to use a CGM; (3) CGM mechanics; (4) reasons for breaks; (5) how often and how long breaks occurred; (6) how diabetes management changed when they were off their CGM; and (7) ways CGM use and diabetes management impacted mood and parent–child relationships. Interviews were conducted with a trained research member, audio recorded via Zoom, and transcribed by an IRB-approved transcription service (rev.com). Interviews lasted approximately 20–30 min. Participants were compensated with a $30 gift card.

Qualitative data coding and analysis was conducted by following the Consolidated Criteria for Reporting Qualitative Research (COREQ) checklist⁵ and was managed by the Vanderbilt University Qualitative Research Core, led by a PhD-level psychologist. A hierarchical coding system was developed and refined using the interview guide and a preliminary review of the transcripts. Transcripts were combined and sorted by code. Transcripts, quotations, and codes were managed using Microsoft Excel 2016 and SPSS version 28.0. We used an iterative inductive/deductive approach to qualitative data analysis.⁶ Inductively, we sorted the coded quotes by coding category to identify higher order themes and relationships between themes. Deductively, we were guided by Social Cognitive Theory,⁷ which emphasizes the individual as an intentional agent driven by the need for a sense of control.

Participants described CGM breaks which could be categorized as “forced” or “voluntary.” Forced breaks were not desired by the adolescent and were caused by factors outside of the adolescent’s control. As seen in Table 1, forced breaks were usually caused by device malfunction, problems with refills, insurance coverage, supply issues, and communication errors (between patient, provider, insurer, pharmacy). Voluntary CGM breaks were times when the adolescent chose to temporarily stop using their CGM. Voluntary breaks were typically related to physical symptoms like skin irritation, and the need for a mental break (Table 1).

Table 1.

Causes and Consequences of CGM Breaks

Causes of CGM breaks	Illustrative quotes
Forced breaks	“… I’m even more annoyed because the problem is between the communication of the hospital and the company... The company’s like, ‘I didn’t get the paperwork,’ and the hospital’s like, ‘I sent them the paperwork.’… It’s like, ‘Can I just please get it back?’” (Participant 4, Age 17) “… every month there’s like a three-day period where my sensors have to be like shipped because of just how our insurance works. So, like at 27 days, my mom has to call in to get them because insurance won’t cover it… I have like a two, three-day break where I have to use my PDM [as a glucometer] to check myself.” (Participant 3, Age 17)
Voluntary breaks	“Just that I don’t like having things on my body all the time. I just need a mental break more. So, then I don’t want to put it back on if I don’t get my break.” (Participant 11, Age 17) “I have somewhat sensitive skin so sometimes…I’ll just get really itchy and it’ll be really uncomfortable and painful...” (Participant 19, Age 16)
Consequences of CGM breaks	“It’s kind of hard to transition from using a sensor to using your sugar tester, because then you have to remember, ‘oh, I have to bring my sugar tester with me’. Because if you forget your sugar tester at home, you obviously ain’t going to be able to use it. You don’t know what your sugar is going to be. And with the sugar tester, you can’t tell where your sugar is going and where it’s been, so you don’t know the patterns. And you don’t know if you’re going to get low here in an hour or if it’s shooting straight up, you can’t tell the difference. So, it’s a lot harder to be accurate with the sugar tester, even though the number is accurate, but you don’t know where it’s going, so you can be a lot healthier whenever you’re on a CGM.” (Participant 1, Age 18) “I’m always annoyed when I have my sugars high. I’m just annoyed and angry because I feel so bad, and I can’t help it. [inaudible] angry...That’s really it. I’m just angry full time. Don’t talk to me. Stay 10 feet away. Personal space. You see my bubble? Don’t go in it.” (Participant 9, Age 18) “I start arguing with my mom because it’s not coming so I feel like it’s her fault. And then it turns into a big argument… Because I feel like if she kept calling (the supplier), it would come, but it doesn’t.” (Participant 20, Age 16)

CGM breaks, both forced and voluntary, led to changes in diabetes management and negative psychosocial outcomes (Table 1). Participants noted difficulties in transitioning to glucometer use because they no longer had the ability to follow patterns/trend blood glucose and because of logistical challenges with using a glucometer. Participants using automated insulin delivery systems noted differences in how the pump worked without a CGM, leading to hyperglycemia. Forced CGM breaks were especially likely to lead to frustration and negatively impacted relationships with caregivers. A limitation of this study is that CGM and glucometer data were not collected, so duration of CGM breaks and glucose monitoring frequency were not known. However, based on a survey question, 50% of our sample reported that they made the transition to using a glucometer easily, 33% reported that they used a glucometer, but it was difficult to remember to check blood glucose, and 17% reported that they did not check blood glucose during breaks from their CGM. These responses demonstrate the difficulties in transitioning back to glucometer use during a CGM break.

Diabetes technologies continue to rapidly evolve, with CGMs and AID systems now recommended for most youth with T1D.² This study highlights the need to educate adolescents and their caregivers about how these devices work together—and, notably, how they work differently when CGMs are not active—to ensure safe monitoring of glucose levels and appropriate diabetes management. In addition, our study offers further support for the need for improved insurance coverage and communication between prescribers, insurers, third party suppliers, and manufacturers to minimize forced CGM breaks. Uninterrupted access to CGMs and education about changing diabetes management during time off CGMs, coupled with tailored approaches to address adolescents’ barriers to consistent CGM use, are critical to allow adolescents the ability to realize the glycemic benefits of these devices.

Author Contributions

K.D., S.J., K.B., and D.S. conceived the study design. A.P., K.B., and D.S. performed qualitative analyses. All authors contributed to the discussion, edited the article, and approved the final version of the article.

Guarantor Statement

K.D. is the guarantor of this work and, as such, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Author Disclosure Statement

The authors have reported no relevant conflicts of interest.

Funding Information

This work was supported by the National Institutes of Health (R01DK121316). K.D. was supported by the Katherine Dodd Faculty Scholars Program.