Flash Glucose Monitoring Technology Impact on Diabetes Self-Care Behavior

Abstract

Individuals with diabetes play a significant role in the control of their condition by participating in their own care. Self-monitoring of blood glucose is of particular importance in maintaining adequate glycemic control but when obtained using traditional fingerstick methods, is often limited with by cost, fear of needles or pain and inconvenience. Flash glucose monitoring is an innovative technology available to address these barriers and help people with diabetes better manage their blood glucose levels. Data demonstrating increased frequency in glucose monitoring, patient perspectives related to self-care behaviors, and implications for practice and future research are described.

‘Diabetes self-care involves a range of activities such as self-monitoring of blood glucose (SMBG), diet, physical activity, and medication adherence.’

Individuals with diabetes have been shown to have a large impact on the progression of their disease by participating in their own care. ¹ Diabetes self-care involves a range of activities such as self-monitoring of blood glucose (SMBG), diet, physical activity, and medication adherence. SMBG is of particular importance, especially for those individuals dependent on insulin for adequate glycemic control. Monitoring blood glucose allows the patient to assess glycemic status and initiate appropriate steps (adjustments in diet, exercise, medication) in a timely manner to achieve glycemic targets. Despite the benefits of SMBG, a study examining monitoring practices in the United States found that just 26% of persons with diabetes using insulin checked their blood glucose at least daily. ² Frequently cited barriers to SMBG include the cost of test strips and needles, fear of needles and pain, inconvenience, and unconducive environment for testing. ³

Fortunately, technology is evolving and new devices are available to address these barriers and help people with diabetes better manage their blood glucose levels. One such example of this innovation is the flash glucose monitoring system (FGMS). The FGMS uses a subcutaneous glucose sensing technology to detect glucose levels in interstitial fluid. ⁴ Glucose is measured automatically every minute, and readings are stored in 15-minute intervals. The system is composed of a disposable sensor and a handheld “reader” to download the blood glucose information. This can be done retrospectively or on-demand by scanning the sensor with the reader. Each reading displays the past 8 hours of glucose information, a current glucose, and a trend arrow that indicates the rate and direction of change in glucose levels. No fingerstick calibrations are required for the system to remain accurate as the sensors are factory calibrated.

Analysis of FGMS users found a higher frequency of glucose monitoring correlated with improved glucose control (less time in hypoglycemia and lower glucose variability) and reduced estimated A1c.^5-7 Data demonstrating increased frequency in glucose monitoring, patient perspectives related to self-care behaviors, and implications for practice and future research are described below.

Increases in Glucose Monitoring Behavior

A number of experimental studies have demonstrated Increases in glucose-monitoring in patients using the FGMS as compared to traditional fingerstick testing.^8,9 A multi-center non-masked, randomized controlled trial evaluated the frequency of glucose monitoring in patients with type 1 diabetes (n=139) using the FGMS or traditional fingerstick glucometers. ⁸ Those patients randomized to intervention with the FGMS demonstrated an increase in the frequency of glucose monitoring from 5.4 fingerstick checks daily at baseline to 15.1 sensor scans daily using the FGMS technology. The number of fingerstick tests obtained by the control group was consistent throughout the study (5.8 checks daily at baseline to 5.6 checks daily at 6 months).

Increases in glucose monitoring with the FGMS have also been seen in patients with type 2 diabetes. An open-label, open-access extension study in insulin-dependent adults with type 2 diabetes (n=139) found that, on average, participants using the FGMS obtained a sensor-scanned reading 7.2 ± 3.5 times/day. ⁹ This compared to a baseline mean 3.9 ± 1.2 tests/day frequency using fingerstick testing.

Glycemic control and self-monitoring is particularly challenging in the adolescent population.^10-12 A prospective study of 75 pediatric (age range 2-19) patients with type 1 diabetes found a statistically significant difference in frequency of glucose monitoring when patients used the FGMS as compared to fingerstick testing (11.6 versus 2.87 checks/day, p<0.001). ¹³

Patient Perspectives of FGMS

Several factors contribute to the increased glucose monitoring frequency seen with the FGMS. A qualitative analysis explored patient experience with the FGMS after 6 months of use. ¹⁴ Forty patients with type 1 diabetes were included in the thematic analysis using a grounded theory approach. As compared to traditional fingerstick glucose monitoring, patients using FGMS had less pain and scarring, less concern about using and depleting testing supplies, and less environmental barriers to testing (do not have to wash hands, can test while exercising/working). As a result, patients reported testing their blood sugars more frequently. Patients appreciated the immediacy of the result and used the trend arrows to “predict and plan.” Patients reported more engagement in their self-management and a greater sense of control of their condition.

Patients report a greater understanding of how insulin, food, and physical activity affect their blood glucose levels when the FGMS is paired with lifestyle behavior tracking tools like food diaries and mobile apps.^15,16 Patients were empowered to make changes in their eating habits based on the effect the food had on their blood sugar. Patients also felt less worry or uncertainty of blood sugar status while undertaking physical activity.

Implications for Practice

The many benefits FGMS provides to patients are clear from the data previously discussed. Additionally, FGMS provides significant benefit to providers managing these patients’ diabetes care. Patients are able to use either a hand-held receiver to track their blood sugars which can then be downloaded by the patient at home or at the provider’s office. Patients can alternatively utilize their mobile devices, if compatible, with the application available from the manufacturer. If this option is chosen, data can be immediately shared with the provider’s office, each time the patient scans their sensor, if the patient elects to do so. An additional benefit to the provider is improved accessibility. Retail pharmacies are able to bill commercial prescription insurance plans or utilize manufacturer rebates for FGMS requiring only an electronic prescription be sent to the patient’s preferred pharmacy. Medicare recipients have coverage of FGMS through contracted medical suppliers if they are using three or more insulin injections daily and checking BG’s at least 4 times daily. Although coverage does exist, shared copays can remain costly inhibiting access to the technology. If cost is not a barrier, providers could consider prescribing FGMS for patients with hypoglycemia unawareness, glucose variability, or really, any patient who would like to have better ability to monitor BG without going through the tedious process of checking fingersticks. Cost-benefit analysis of FGMS in Type 1 diabetes have demonstrated high clinical efficacy in the presence of high, but potentially acceptable cost if the patient confers significant benefit from wearing it. ¹⁷

FGMS offers ample data for providers to more readily identify trends in blood glucose values, more confidently suggest changes in medication therapy, and if patient record keeping is optimized, utilize food and medication administration logs to explain variability in blood glucose. Although no published data exists analyzing clinician satisfaction, testimonial appreciation of the increased volume of data that is given in the reports derived from FGMS is consistently positive. Education should be provided by a trained clinician on the difference between sensor glucose reading and results from a glucometer as they can be different, particularly in times of glucose lability as FGMS measures interstitial glucose vs. blood glucose measured by a traditional meter. The result of this is a slight lag in the FGMS in the sensor updating glucose readings making it essential that patients understand that if BG is changing rapidly or if they are experiencing significantly high or low BG’s, their sensor may not be accurate and they should refer back to a fingerstick. The system incorporates trending arrows and patients should be educated on their meaning as well as how to use them to interpret where blood glucose is heading. These predictions may guide choices regarding planned food intake or activity to avoid hypo- and hyperglycemic excursions. Although predictive arrows are provided to patients when they scan their sensor, alerts and alarms are not currently available with FGMS to warn patients of changing BG’s if they do not take the initiative to scan their sensor. This may make it less useful for those patients with highly variable blood glucose, or those with hypoglycemia unawareness than continuous glucose monitoring systems that transmit data to a receiver in real-time and alert patients or care-givers to potential highs or lows without any action of the patient.

Implications for Future Research

While data demonstrate a significant increase in glucose self-monitoring with FGMS compared to traditional fingerstick testing and patients describe the use of FGMS affecting other self-care behaviors, no formal assessment of change in eating habits or physical activity is available. The Summary of Diabetes Self-Care Activities Measure is a reliable, valid self-report measure of diabetes self-management that could be used to assess the impact of FGMS on nutrition and physical activity. ¹⁸ Results may be valuable in promotion and support of lifestyle modifications in patients with diabetes.