Barriers to Use of Continuous Glucose Monitoring Among Adults with Type 2 Diabetes

Summary:

This retrospective study assessed barriers to CGM use among 100 adults with type 2 diabetes receiving endocrinology care. Patient preference was the most common reason for non-use (n=47). Nearly half of patients had no CGM discussion documented (n=42), and financial (n=9) and phone compatibility (n=2) barriers were less common.

1. Introduction

Continuous glucose monitoring (CGM) among adults with type 2 diabetes (T2D) improves glycemia and quality of life and reduces hypoglycemia [1,2]. However, use of CGM among adults with T2D in the U.S. ranges from 1-13%, with disparities by race, ethnicity, insurance type, and socioeconomic status [3,4]. Increasing CGM adoption is one potential approach to improve diabetes outcomes for adults with T2D. Prior work has evaluated barriers to CGM adoption in primary care, but barriers in specialty care, where practice patterns and patient characteristics may differ, are not clear [5,6]. In this study, we aimed to identify barriers to CGM utilization among adults with T2D receiving endocrinology care to inform efforts to increase CGM uptake in this population.

2. Materials and Methods

2.1. Clinical Setting & Study Design

A retrospective chart review evaluated documented barriers to CGM use. Clinical documentation was reviewed, in random order, from a convenience sample of all visits for T2D in February 2024 across 8 endocrinology clinics in an integrated health system in Pennsylvania. Patients with type 1, gestational, or other diabetes were excluded. Data extracted from clinical documentation using a structured form (Supplemental Table 1) included demographics, HbA1c, diabetes duration, complications, medications, and free-text documentation regarding CGM use. This study was conducted as the first phase of a quality improvement project and approved by the Quality Review Committee of UPMC (Project # 4836).

2.2. Data Analysis

Descriptive statistics summarized patient characteristics. Thematic analysis of free-text documentation identified barriers to CGM use. One endocrinologist recorded quotations from clinical documentation regarding CGM use. Next, codes describing reasons for non-use were developed and applied to direct quotations by two endocrinologists. Intercoder percent agreement was 96%; disagreements were resolved by consensus. When there was no CGM discussion documented in the visit note, up to two prior endocrinology notes were reviewed to assess whether CGM had previously been addressed. CGM device type was not consistently documented for patients with prior use and was not included in analysis. Finally, the association of patient characteristics with CGM discussion was assessed in exploratory analysis. Data analysis occurred from March–May 2024.

3. Results

The cohort was 51% female with mean HbA1c 7.9%, (63 mmol/mol, Table 1). The most common reason documented for lack of current CGM use was patient preference in 47 cases (Table 2), including 16 patients with prior use. Most patients did not have specific reasons documented for preference not to use CGM. Among those who had previously used CGM, the most common reason for non-use was skin reactions to sensor adhesive (n=4). In 42 cases, there was no documentation that CGM was discussed. Financial barriers (n= 9) and phone incompatibility (n=2) were less common. In exploratory analysis, use of basal-bolus insulin was more common among patients with documented CGM discussion; no insulin use and basal insulin alone were more common among patients with no CGM discussion (Supplemental Table 2).

Table 1:

Patient Characteristics

Characteristic	Overall cohort N=100
Sex; n (%)
Male	49 (49%)
Female	51 (51%)
Age in years; mean (SD)	65.4 (12.0)
Race/Ethnicity; n (%)
White, non-Hispanic	92 (92%)
Black, non-Hispanic/Other	8 (8%)
Insurance type; n (%)
Commercial/Other	34 (34%)
Medicare	58 (58%)
Medicaid	8 (8%)
Duration of diabetes in years; mean (SD)	13.8 (8.1)
HbA1c %; mean (SD)	7.9 (1.9)
mmol/mol	63 (20.8)
Macrovascular complications; n (%)
Coronary artery disease	23 (23%)
Stroke/TIA	4 (4%)
Peripheral arterial disease	5 (5%)
Microvascular complications; n (%)
Retinopathy	18 (18%)
Nephropathy	31 (31%)
Neuropathy	51 (51%)
Insulin treatment; n (%)
None	26 (26%)
Basal Insulin only	30 (30%)
Basal and short-acting insulin	36 (36%)
Short-acting insulin alone	2 (2%)
Pre-mixed insulin or U-500	6 (6%)
Non-insulin treatment; n (%)
Metformin	66 (66%)
GLP-1 agonist	63 (63%)
SGLT2 inhibitor	30 (30%)
Sulfonylurea	21 (21%)
DPP-4 inhibitor	7 (7%)
Glinides	6 (6%)
Thiazolidinediones	1 (1%)

Table 2:

Documented Reasons for Lack of CGM use among Adults with T2D (N=100)

Reason n(%)
Patient preference, no prior use	31 (31%)
No specific reason cited	26 (26%)
Preference for CBG	4 (4%)
Avoid sensor attached to body	1 (1%)
Patient preference, prior use	16 (16%)
No specific reason cited	4 (4%)
Dermatitis/reaction to adhesive	4 (4%)
Alarms	2 (2%)
Preference for CBG	2 (2%)
Difficulty with sensor falling off	2 (2%)
Connectivity with smart phone	1 (1%)
Contraindicated	1 (1%)
Phone incompatible	2 (2%)
Financial	9 (9%)
Not covered by insurance	7 (7%)
High copay	2 (2%)
No CGM discussion documented	42 (42%)

4. Discussion

The study highlights barriers to the adoption of CGM among adults with T2D in a specialty care setting. Patient preference was the most common reason documented for lack of CGM use. However, nearly an equal number of patients did not have discussion of CGM documented. Reasons for non-use align with existing evidence on factors that prevent CGM uptake, including alarms, skin irritation, and sensor adhesion issues [7,8]. Additional barriers to CGM use, including concerns about social stigma [9], lack of patient education [8,10], and difficulty interpreting CGM data [11] have also been described. Educational resources and personalized support from diabetes care teams may help patients address these barriers and promote long-term use of CGM to support achievement of diabetes treatment goals [12].

Financial barriers were documented for nearly 1 in 10 patients in this study. At the time of this study, CGM was covered for Medicare recipients with T2D prescribed any insulin. While Medicaid policies vary by state, CGM was similarly covered for Medicaid recipients in Pennsylvania during the study period. However, lack of re-assessment of changing policies and financial barriers despite insurance coverage may still lead to low CGM uptake. Prior work has found that expanded coverage of CGM under Medicaid, including full subsidies, is associated with high CGM adherence [13], highlighting improved insurance coverage and lower out-of-pocket cost as one opportunity to remove barriers to CGM use for people with T2D [14–16].

Finally, nearly half of patients had no CGM discussion documented. Factors which contribute to insurance coverage and clinical utility of CGM, including insulin use, may have contributed to lack of CGM discussion. However, half of patients who lacked documentation of CGM discussion used insulin. Therapeutic inertia, which can delay diabetes treatment changes in response to suboptimal glycemia [17,18], may impact initiation of tools such as CGM. Efforts to enhance both patient and provider awareness of CGM benefits, promote routine re-evaluation insurance coverage and other barriers to use, and enhance troubleshooting to support adherence, may facilitate increased uptake and persistence.

This study has several limitations. First, reliance on clinical documentation limits accuracy of determining whether CGM was discussed and may lead to underestimation of financial and other barriers. This study included visits conducted during a single month, which may result in sampling bias if there were differences in patients or clinicians with visits in that time period versus a longer time span. In addition, as this study was conducted within an endocrinology division of a single health system, results may not be generalizable to other settings, such as primary care or broader geographies. Finally, this study was not designed to evaluate the association of patient characteristics with CGM use or discussion, so these results should be interpreted as exploratory only.

5. Conclusion

Despite known benefits for adults with T2D, several barriers hinder widespread adoption of CGM in this population. Targeted education and ongoing support, improving clinician-patient communication regarding CGM, and addressing insurance and financial barriers are essential steps to enhance CGM utilization among adults with T2D.

Abbreviations:

CGM

Continuous Glucose Monitoring

T2D

Type 2 Diabetes

HbA1c

Hemoglobin A1c