rtCGM Systems Research Articles

Acceptability and experiences of real-time continuous glucose monitoring in adults with type 2 diabetes using insulin: a qualitative study

AimsTo explore the lived experiences of initiating real-time continuous glucose monitoring (rt-CGM) use in individuals with type 2 diabetes using insulin.MethodsTwelve semi-structured interviews were conducted amongst individuals with type 2 diabetes taking insulin who were enrolled in the 2GO-CGM randomised controlled trial and had completed 3 months of rtCGM. Interviews were transcribed verbatim and analysed to identify common themes regarding their experiences.ResultsThe interviews revealed three key themes: i) rtCGM as a facilitator of improved health behaviours; ii) the acceptability of rtCGM systems compared to capillary blood glucose testing; and iii) barriers to the continual usage of rtCGM technology – including: connection difficulties, longevity of the sensors, and local cutaneous reactions to the sensor adhesive.ConclusionAdults on insulin with type 2 diabetes find rtCGM systems widely acceptable, and easier to engage with than traditional self-monitoring of capillary blood glucose.

Association Between Adherence, A1C Improvement, and Type of Continuous Glucose Monitoring System in People with Type1 Diabetes or Type2 Diabetes Treated with Intensive Insulin Therapy.

Use of continuous glucose monitoring (CGM) systems by people with diabetes is associated with improved glycemic outcomes, including lower glycated hemoglobin (A1C). Less is known about adherence to CGM systems, whether glycemic outcomes are impacted by levels of adherence, or whether adherence rates differ between types of CGM systems-intermittently scanned CGM (isCGM) or real-time CGM (rtCGM). A retrospective analysis of de-identified US administrative health claims and linked laboratory data was conducted using the Merative™ MarketScan® Research Database. The cohort included CGM-naïve people with type1 diabetes (T1D) or type2 diabetes treated with intensive insulin therapy (T2D-IIT) who initiated rtCGM or isCGM between August1, 2019 and March31, 2021 (defined as the index date). Adherence was calculated over a 12-month period using the proportion of days covered (PDC) with PDC ≥ 0.8 defined as adherent. A1C values were obtained within 6months of the index date. A total of 7669 individuals were identified. Subgroups included T1D using isCGM (n = 1578), T1D using rtCGM (n = 1244), T2D-IIT using isCGM (n = 3567), and T2D-IIT using rtCGM (n = 1280). After 12months, PDC was 0.71 (0.30)-0.72 (0.31) (mean(SD)) for T1D and T2D-IIT rtCGM users and 0.55 (0.34)-0.56 (0.34) for T1D and T2D-IIT isCGM users. The proportion of adherent users (PDC ≥ 0.8) was 56.8-59.7% for rtCGM users and 36.3-37.6% for isCGM users. Overall, regardless of diabetes type, the odds of adherence were over two times higher for rtCGM users compared to isCGM users. For those with available A1C information (T1D n = 213; T2D-IIT n = 346), independent of CGM type, adherence to CGM was associated with a greater reduction in A1C and more people reaching A1C targets of < 7.0% or < 8.0%. For people with T1D or T2D-IIT, higher adherence to CGM is associated with greater reductions in A1C, and higher adherence rates were observed with rtCGM systems than with isCGM systems.

142-LB: Cost-Effectiveness of Real-Time Continuous Glucose Monitoring (rt-CGM) vs. Intermittent-Scanning Continuous Glucose Monitoring (is-CGM) in Patients with Type 2 Diabetes on Multiple Daily Injections of Insulin (T2D MDI) in Canada

Rt-CGM systems provide real-time glucose values, hypo- and hyperglycemia alerts, and predictive “urgent low soon” alerts that have been shown to improve glycemic outcomes and reduce severe hypoglycemic events (SHEs) in patients with T2D, without the need for periodic scanning. The economic value of rt-CGM vs is-CGM is unknown for patients with T2D MDI in Canada. We conducted a cost-effectiveness analysis comparing the two systems for this patient population using the INESSS Canadian payer perspective. ­ A 30-year analysis was performed using the validated ECHO-T2DM. Patient characteristics were sourced from Karter (2021). Efficacy and safety were derived from the DIAMOND T2D and REPLACE RCTs. The HbA1c difference of -0.33 (favoring rt-CGM) was derived using Bucher's adjusted indirect comparison, SHE rates were 0.014 and 0 Per Person-Year (PPY) for is-CGM and rt-CGM, respectively, and severe hyperglycemia/DKA rates were proxied by the difference in time above range (0.0313 and 0 PPY, respectively). Costs and disutility weights were sourced from published Canadian literature and discounted at 1.5% annually. A reduction in fear of hypoglycemia (FOH) utility was sourced from the ALERTT1 RCT. Sensitivity analyses were performed. Rt-CGM was associated with quality-adjusted life year gains of 0.346 and incremental costs of CAD 5,737, with an incremental cost-effectiveness ratio (ICER) of CAD 16,598. No DKA events for is-CGM and a 50% reduction in FOH utility increased the ICERs to CAD 30,987 and CAD 29,116, respectively. ICER was CAD 2,278 when both CGM costs were reduced by 50% and rt-CGM became cost-saving (dominant) at a 65% reduction. These results suggest rt-CGM is cost-effective vs is-CGM in patients with T2D MDI in Canada. These findings can inform government and commercial healthcare decision-makers when considering reimbursement of CGM systems. Disclosure H. Alshannaq: Employee; Dexcom, Inc., Other Relationship; Vertex Pharmaceuticals Incorporated. G. J. Norman: Employee; Dexcom, Inc. M. Willis: None. A. Nilsson: None. Funding Dexcom, Inc.

Levelling up: should all continuous glucose monitoring systems be available on prescription in the NHS?

Dear Editor, the launch of the FreeStyle Libre intermittently scanned continuous glucose monitoring system (also known as Flash or isGCM) on prescription in November 2017 and subsequently Libre 2 has brought about a paradigm shift in the widespread availability of CGM for people living with type 1 diabetes (T1D) in the UK.1 Libre has been available for self-funding since 2014 and real-time (rt) CGM has been around commercially for a decade or so before this.2 Strong clinical leadership from Professor Partha Kar and colleagues from the Diabetes Technology Network along with campaigning from patient organisations have undoubtedly accelerated and catalysed this change with over 69% of the English population of people living with T1D being prescribed a Libre, and – with the exception of two (out of 42) integrated care systems – all other systems have at least half of their population of people living with T1D on Libre from almost zero five years earlier.3 This growth occurred prior to the publication of 2022 NICE guidance (NG17)4 recommending all forms of CGM be offered to all people living with T1D. Previous NHS England guidelines suggested about 20% of the T1D population would be eligible for FreeStyle Libre and funding for sensors up to this number of patients was available centrally for a limited time. National Diabetes Audit data for rtCGM from 2020–215 (until recently rtCGM was not available on prescription at all) show that the majority of specialist adult diabetes care providers in England had none or a miniscule percentage of their patients using rtCGM; many of these same units had large numbers of people using FreeStyle Libre. (See Figure 1.) These data would suggest that there were (and still may be) large parts of the country where, for adults with T1D, rtCGM was (or still may be) either not available or difficult to access. The data would further suggest that there is an even greater variation in the use of rtCGM than there is with FreeStyle Libre. The recent update to NG174 on the use of all forms of CGM has undoubtedly encouraged companies to include some of their rtCGM products on prescription, but not all. At present there appears to be inconsistent, non-transparent and often complicated local schemes for providing access to many rtCGM systems. This makes delivery on the promise of NG17 unnecessarily difficult -- especially in terms of giving people with T1D a genuine choice in the device they use to monitor their glucose levels. If we are to fully meet the glucose monitoring needs of our adult population of people with T1D, surely the time has come for all CGM systems to be available on prescription. This would create a level playing field for people living with diabetes and those who provide their care, thereby affording access based on NICE 2022 criteria in keeping with the founding principles of the NHS. There are no conflicts of interest declared.

Development and Psychometric Assessment of a Manufacturer Independent Knowledge Questionnaire on Real Time Continuous Glucose Monitoring for insulin-treated People with Diabetes

Abstract Background To benefit from real-time continuous glucose monitoring (rtCGM), users need practical skills and in-depth knowledge to analyze the glucose data appropriately and adapt insulin therapy accordingly. To assess the user’s knowledge about rtCGM, a psychometric knowledge test was developed and evaluated. Method Experts on the use of rtCGM systems defined central knowledge contents in a Delphi process and developed a knowledge test comprising 40 multiple-choice items. For test-statistical review, people with insulin-treated diabetes and members of diabetes teams answered the knowledge test. Results The 122 diabetes team members (age 46 (11) years; mean (SD)) and the 111 people with insulin-treated diabetes (age 42 (14) years, diabetes duration 20 (14) years, users of insulin pumps 64 %, previous usage of rtCGM 38 %, HbA1c 8.0 % [95 % CI 7.7–8.3] (64 mmol/mol [60–67]) had different levels of experiences using rtCGM systems. The internal consistency (Cronbach’s alpha) of the knowledge test was 0.92 for the whole sample, for people with diabetes 0.94, and for diabetes team members 0.84. Item difficulty ranged between 0.12 and 0.88 in people with diabetes and between 0.27 and 0.97 among diabetes team members. On average, people with diabetes answered 24.1 (9.9) items correctly, diabetes team members 29.2 (5.2) (p &lt; 0.001); people with diabetes and previous rtCGM-experience had a higher knowledge compared to people without previous experience (29.2 (6.2) vs. 21.0 (10.4) (p = 0.001)). The quality of glucose control (measured by HbA1c) of the people with diabetes was significantly associated with the sum-score of the questionnaire (rho = –0.48, p &lt; 0.001). Conclusion The “rtCGM-Profi-Check” knowledge test provides high internal consistency, high selectivity, and content validity. It is suitable for objective, reliable, and valid assessment of the indispensable knowledge of people with diabetes to use different rtCGM systems successfully. The questionnaire is manufacturer-independent and is suitable to evaluate the needs and success of rtCGM education among persons with diabetes.

Outcomes and Healthcare Provider Perceptions of Real-Time Continuous Glucose Monitoring (rtCGM) in Patients With Diabetes and COVID-19 Admitted to the ICU.

We assessed the clinical utility and accuracy of real-time continuous glucose monitoring (rtCGM) (Dexcom G6) in managing diabetes patients with severe COVID-19 infection following admission to the intensive care unit (ICU). We present retrospective analysis of masked rtCGM in 30 patients with severe COVID-19. rtCGM was used during the first 24 hours for comparison with arterial-line point of care (POC) values, where clinicians utilized rtCGM data to adjust insulin therapy in patients if rtCGM values were within 20% of point-of-care (POC) values during the masked period. An investigator-developed survey was administered to assess nursing staff (n = 66) perceptions regarding the use of rtCGM in the ICU. rtCGM data were used to adjust insulin therapy in 30 patients. Discordance between rtCGM and POC glucose values were observed in 11 patients but the differences were not considered clinically significant. Mean sensor glucose decreased from 235.7 ± 42.1 mg/dL (13.1 ± 2.1 mmol/L) to 202.7 ± 37.6 mg/dL (11.1 ± 2.1 mmol/L) with rtCGM management. Improvements in mean sensor glucose were observed in 77% of patients (n = 23) with concomitant reductions in daily POC measurements in 50% of patients (n = 15) with rtCGM management. The majority (63%) of nurses reported that rtCGM was helpful for improving care for patients with diabetes patients during the COVID-19 pandemic, and 49% indicated that rtCGM reduced their use of personal protective equipment (PPE). Our findings provide a strong rationale to increase clinician awareness for the adoption and implementation of rtCGM systems in the ICU. Additional studies are needed to further understand the utility of rtCGM in critically ill patients and other clinical care settings.

Evaluation of the SPECTRUM training programme for real-time continuous glucose monitoring: A real-world multicentre prospective study in 120 adults with type 1 diabetes.

Comprehensive knowledge, specific skills and data-analysis competences are prerequisites for the successful use of continuous glucose monitoring (CGM) systems. SPECTRUM is a structured training programme for real-time CGM (rtCGM) consisting of a web-based introduction and six group sessions of 90min each. The 'CGM-TRAIN study' evaluated the efficacy and acceptance of SPECTRUM and rtCGM systems among adults with insulin therapy. Participants (n=120) were recruited from 10 German diabetes centres in which they were treated under usual care conditions. Outcome measures were rtCGM knowledge, practical skills, satisfaction with the training programme, satisfaction and acceptance of rtCGM system and glycaemic control. Data were collected at study entry, after training completion and at 6-month follow-up. All participants were diagnosed with type 1 diabetes (56% women, mean age 42.4±13.4years, diabetes duration 21.6±11.6years), 110 participants completed the course. After training completion, rtCGM-specific knowledge had improved by 43% (scale: 0-40 points) from 21.2±7.6 to 30.4±4.5 points; p<0.001. The knowledge-level persisted until follow-up (29.4±4.5). Participants were able to master nearly all the practical requirements of the technology. In addition, rtCGM was highly accepted, and participants were motivated to use their systems continuously. HbA1c improved slightly from 61±14mmol/mol (7.7±1.3%) before training to 60±14mmol/mol (7.6±1.3%) at follow-up (p=0.04). The training programme itself was favourably rated by participants. Under usual out-patient daily care conditions, the training programme SPECTRUM improved knowledge and skills about rtCGM in adults with type 1 diabetes. This was associated with a reduced HbA1c , high satisfaction and acceptance of rtCGM (Clinical Trials Registry no.: DRKS00014380).

Effectiveness of real-time continuous glucose monitoring to improve glycaemic control and pregnancy outcome in patients with gestational diabetes mellitus: a study protocol for a randomised controlled trial

IntroductionReal-time continuous glucose monitoring (rt-CGM) informs users about current interstitial glucose levels and allows early detection of glycaemic excursions and timely adaptation by behavioural change or pharmacological intervention. Randomised controlled...

Basics and use of continuous glucose monitoring (CGM) in diabetes therapy

Abstract Background For a long time, self-monitoring of blood glucose (SMBG) was widely viewed as the essential glucose measurement procedure in the therapy of insulin-treated people with diabetes. With increasing accuracy and simplified handling of continuous glucose monitoring (CGM) systems, this evolving technology challenges and at least partly replaces SMBG systems. Content Sensors of all currently available CGM systems measure glucose levels in the subcutaneous interstitial fluid for 6–14 days. The only available implantable sensor facilitates a measurement span of up to 6 months. Depending on the used system, glucose levels are either shown in real time (rtCGM systems) or after scanning (iscCGM systems). Functions such as alerts, alarms and trend arrows and data presentation encourage independent self-management of diabetes therapy. The high frequency of glucose data and the multitude of existing functions require an extensive training of people with diabetes and their caregivers. Summary CGM systems provide a much more detailed picture of glycemia in people with diabetes. Educated patients can use these data to react adequately to their glucose levels and therefore avoid hypoglycemic and hyperglycemic events. Studies showed that glycated hemoglobin (HbA1c) levels and hypoglycemic events can be significantly reduced by frequent use of CGM systems.

Impact of CGM on the Management of Hypoglycemia Problems: Overview and Secondary Analysis of the HypoDE Study.

Hypoglycemia remains the limiting factor of near-normal glucose control in people with diabetes using insulin therapy. Continuous glucose monitoring (CGM) may be able to avoid hypoglycemia and support the management of hypoglycemia problems in clinical care. Real-time continuous glucose monitoring (rtCGM) systems provide alerts if certain predetermined hypo- or hyperglycemic thresholds are exceeded. The combination of rtCGM systems with insulin pumps allows insulin delivery to be suspended if glucose falls below certain predefined thresholds. This might also support avoidance of hypoglycemia. More sophisticated closed-loop systems allow a semiautomatic insulin dosage, which also have the potential for the prevention of hypoglycemia. In this overview, we discuss and illustrate (1) the efficacy of CGM for intervention in people with hypoglycemia problems and for the avoidance of biochemical as well as clinical hypoglycemia; (2) the potential of CGM technology for the identification of people with diabetes who are at risk for hypoglycemia problems; and (3) the implications of the current state of the art for future research regarding CGM and hypoglycemia. As an example, how rtCGM data can facilitate identification of people with diabetes and an elevated risk of hypoglycemia, a secondary analysis of the HypoDE data is presented. We conclude that CGM technology can assist in the reliable identification of people with diabetes who are at risk for hypoglycemia problems, is a powerful intervention for the avoidance of mild as well as severe hypoglycemia, and can also stimulate research on the course of hypoglycemia problems.

Clinical Implications of Real-time and Intermittently Scanned Continuous Glucose Monitoring.

Two types of continuous glucose monitoring (CGM) systems are now available: real-time CGM (rtCGM) and intermittently scanned (isCGM). Current rtCGM systems automatically transmit a continuous stream of glucose data to the user, provide alerts and active alarms, and transmit glucose data (trend and numerical) in real time to a receiver, smart watch, or smartphone. The current isCGM system provides the same type of glucose data but requires the user to purposely scan the sensor to obtain information, and it does not have alerts and alarms. Both CGM technologies have significant advantages over self-monitoring of blood glucose; however, differences in the features and capabilities of the two approaches must be considered when guiding patient selection of the system that meets their individual needs.

The Effect of Reduced Self-Monitored Blood Glucose Testing After Adoption of Continuous Glucose Monitoring on Hemoglobin A1c and Time in Range.

The effectiveness of real-time continuous glucose monitoring (rtCGM) in adults with diabetes treated with insulin injections was evaluated in the 24-week DIAMOND clinical trial comparing rtCGM users to a control group using self-monitored blood glucose (SMBG) testing ( Clinicaltrials.gov : NCT02282397). All participants were instructed to use SMBG results for diabetes management decisions; however, SMBG testing frequency varied within the rtCGM group. This brief report evaluated how SMBG frequency changes in the rtCGM group were correlated with glycemic outcomes in the same trial. Baseline and end-of-study hemoglobin A1c (HbA1c) levels, percentages of CGM values in the 70-180 mg/dL target range (time in range [TIR]), mean of daily differences (MODD), and glycemic coefficients of variation (CVs) were compared. The rtCGM group analyzed included 175 participants-99 with type 1 diabetes (T1D) and 76 with type 2 diabetes (T2D). When comparing participants whose SMBG testing frequency decreased by >1/day versus ≤1/day, mean change in HbA1c was similar (-0.9 ± 0.7 percentage points in both groups, P = 0.59), as was change in TIR (+3.9 ± 14.3 vs. +5.7 ± 13.7 percentage points, respectively, P = 0.39). Likewise, when comparing participants in the highest and lowest quartiles of SMBG frequency reduction (≥2.2 vs. ≤0.4 fewer tests/day, respectively), changes in HbA1c (-0.8 ± 0.6 vs. -0.9 ± 0.6 percentage points, respectively, P = 0.52) and TIR (+4.8 ± 13.2 vs. +5.6 ± 12.7 percentage points, respectively, P = 0.98) were similar. The mean (standard deviation [SD]) change in MODD was -8.3 mg/dL (14.8) and -5.5 mg/dL (14.7) for participants who reduced their SMBG frequency by >1 test/day and ≤1 test/day, respectively; the mean (SD) change in CV was -3.6% (5.0) and -1.6% (5.1) for participants who reduced their SMBG frequency by >1 test/day and ≤1 test/day, respectively. These findings suggest that individuals who decrease the frequency of SMBG testing can effectively base some of their diabetes-related treatment decisions on glucose concentrations, trend information, and alarms provided by their rtCGM systems.

JDRF Randomized Clinical Trial to Assess the Efficacy of Real-Time Continuous Glucose Monitoring in the Management of Type 1 Diabetes: Research Design and Methods

While real-time (RT) continuous glucose monitoring (CGM) systems may revolutionize treatment of type 1 diabetes (T1D), there is insufficient evidence currently available to support widespread utilization of these devices. The Juvenile Diabetes Research Foundation (JDRF) CGM Study Group developed a randomized clinical trial to determine if RT-CGM can improve glycemic control and quality of life in children and adults with T1D. This paper presents the research design and methods that are being employed in this study. The JDRF CGM Study Group trial is a randomized, parallel group, efficacy and safety study. Subjects with T1DM who meet eligibility criteria are randomized to either standard self-monitoring of blood glucose (SMBG) alone or use of any of the three current RT-CGM systems as a supplement to SMBG. After the 6-month randomized period, the Control Group is offered use of RT-CGM, and both groups are studied for an additional 6 months. Subjects are divided into two cohorts: the Main Study Cohort includes subjects with baseline glycosylated hemoglobin (HbA1c) 7.0-10.0% inclusive, and the Exploratory Pilot Study Cohort includes subjects with HbA1c<7.0%. Difference in HbA1c is the primary outcome in the Main Study. Other outcomes include the percentage of sensor glucose values within the 70-180 mg/dL range, scores on questionnaires that assess the impact of RT-CGM on living with T1D, and the cost-effectiveness of RT-CGM. Recruitment for the study was completed on December 15, 2007. Results of this clinical trial should help establish whether or not current RT-CGM devices are beneficial to patients with T1D.