Real-life utilization of real-time continuous glucose monitoring: the complete picture

Adolescent-Preferred financial incentives to promote type 1 diabetes Self-Care: A discrete choice experiment

AIMS

This study aimed to quantify preferences for the characteristics of a financial incentives program that would motivate adolescent engagement in type 1 diabetes (T1D) self-care.

METHOD

We performed a discrete choice experiment with 12-18 year-olds with T1D from two pediatric hospital endocrinology clinics (n = 317). We identified key attributes of incentives: (1) monthly value of the reward, (2) payment structure, and (3) difficulty of incentivized behaviors. In twelve choice questions, adolescents chose the incentive option from a pair of profiles that was more likely to motivate them to increase adherence to recommended self-care. Options presented were tailored to adolescents' T1D technology use and perceived difficulty of completing each behavior. We analyzed data using a conditional logit model.

RESULTS

The value of the reward accounted for 60.8% of preferences. Adolescents were willing to accept lower value rewards when incentive payments used positive vs. negative reinforcement (-$10.88 (95% CI: -$12.60, -9.24)) and preferred higher incentives for performing hard vs. easier behaviors (+$14.92 (95% CI: +$12.66, +$17.28)).

CONCLUSIONS

Stated preferences can inform intervention design. Future research will evaluate the external validity of the discrete choice experiment-informed intervention design by assessing adolescent health and behavioral outcomes in a randomized controlled trial.

Generalization of a Deep Learning Model for Continuous Glucose Monitoring-Based Hypoglycemia Prediction: Algorithm Development and Validation Study

Background

Predicting hypoglycemia while maintaining a low false alarm rate is a challenge for the wide adoption of continuous glucose monitoring (CGM) devices in diabetes management. One small study suggested that a deep learning model based on the long short-term memory (LSTM) network had better performance in hypoglycemia prediction than traditional machine learning algorithms in European patients with type 1 diabetes. However, given that many well-recognized deep learning models perform poorly outside the training setting, it remains unclear whether the LSTM model could be generalized to different populations or patients with other diabetes subtypes.

Objective

The aim of this study was to validate LSTM hypoglycemia prediction models in more diverse populations and across a wide spectrum of patients with different subtypes of diabetes.

Methods

We assembled two large data sets of patients with type 1 and type 2 diabetes. The primary data set including CGM data from 192 Chinese patients with diabetes was used to develop the LSTM, support vector machine (SVM), and random forest (RF) models for hypoglycemia prediction with a prediction horizon of 30 minutes. Hypoglycemia was categorized into mild (glucose=54-70 mg/dL) and severe (glucose<54 mg/dL) levels. The validation data set of 427 patients of European-American ancestry in the United States was used to validate the models and examine their generalizations. The predictive performance of the models was evaluated according to the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC).

Results

For the difficult-to-predict mild hypoglycemia events, the LSTM model consistently achieved AUC values greater than 97% in the primary data set, with a less than 3% AUC reduction in the validation data set, indicating that the model was robust and generalizable across populations. AUC values above 93% were also achieved when the LSTM model was applied to both type 1 and type 2 diabetes in the validation data set, further strengthening the generalizability of the model. Under different satisfactory levels of sensitivity for mild and severe hypoglycemia prediction, the LSTM model achieved higher specificity than the SVM and RF models, thereby reducing false alarms.

Conclusions

Our results demonstrate that the LSTM model is robust for hypoglycemia prediction and is generalizable across populations or diabetes subtypes. Given its additional advantage of false-alarm reduction, the LSTM model is a strong candidate to be widely implemented in future CGM devices for hypoglycemia prediction.

Bi-weekly Glycated Albumin Measurement was Useful to Encourage Behavioral Changes in People with Type 2 Diabetes Mellitus

INTRODUCTION

Hemoglobin A1c (HbA1c), representing the average blood glucose over 1-2 months, is the most commonly used glycemic marker in people with diabetes. Glycated albumin (GA) reflects the average blood glucose over the most recent 1-2 weeks. We considered whether the faster response of GA compared with HbA1c could make people with diabetes realize their glycemic control intuitively and effectively.

METHODS

We randomized 61 people with diabetes into the control and intervention groups. Blood samples were collected from both every fortnight over an 8-week period (five times; visit 1-5). Only the intervention group was notified of the GA levels on the same day. At the beginning and end of the study, International Physical Activity Questionnaire and Eating Behavior Questionnaire assessments, and body composition measurements were conducted.

RESULTS

The body weight change was significantly lower in the intervention group at visit 2 and visit 5. The percent body fat change was lower, while the percent skeletal muscle mass change at visit 5 was higher in the intervention group. Increasing GA trend was observed in the control group, but not in the intervention group. The fasting plasma glucose and HbA1c changes at visit 5 were similar in the two groups. Physical activity level change tended to be higher in the intervention group. The YN Eating Behavior Questionnaire score changes were similar in the two groups.

CONCLUSION

Bi-weekly GA measurement over an 8-week period in people with type 2 diabetes induced behavioral changes. Development of this method is expected to improve diabetes management.

TRIAL REGISTRATION

UMIN000037795.

Adolescent ambivalence about diabetes technology-The Janus faces of automated care

The Janus face metaphor approach highlights that a technology may simultaneously have two opposite faces or properties with unforeseen paradoxes within human-technology interaction. Suboptimal acceptance and clinical outcomes are sometimes seen in adolescents who use diabetes-related technologies. A traditional linear techno-determinist model of technology use would ascribe these unintended outcomes to suboptimal technology, suboptimal patient behavior, or suboptimal outcome measures. This paradigm has demonstratively not been successful at universally improving clinical outcomes over the last two decades. Alternatively, the Janus face metaphor moves away from a linear techno-determinist model and focuses on the dynamic interaction of the human condition and technology. Specifically, it can be used to understand variance in adoption or successful use of diabetes-related technology and to retrospectively understand suboptimal outcomes. The Janus face metaphor also allows for a prospective exploration of potential impacts of diabetes-related technology by patients, families, and their doctors so as to anticipate and minimize potential subsequent tensions.

Use of Patient-Reported Outcomes for Assessing Diabetes Outcomes

The treatment of diabetes can be complex and overwhelming for patients as it demands persistent attention to lifestyle management, adherence to medications, monitoring of side effects of drugs, and management of devices for glucose monitoring and/or insulin infusion. Therefore, understanding patient-reported outcomes (PROs) that provide direct insight into the patient's experience with diabetes is crucial for optimizing diabetes management.This review provides an overview of commonly used PRO questionnaires that assess different aspects of diabetes management.

Predicting Glycated Hemoglobin Through Continuous Glucose Monitoring in Real-Life Conditions: Improved Estimation Methods

BACKGROUND

The adoption of continuous glucose monitoring (CGM) already helps to improve glycemic control in diabetes. When coupled with appropriate data analysis techniques, CGM also provides dependable estimates for significant metrics, like glycated hemoglobin (HbA1c). Findings from the REALISM-T1D study can boost HbA1c estimation methods in diabetes care and stimulate their use in clinical practice.

METHODS

Continuous glucose monitoring data of 27 adults affected by type-1 diabetes were acquired by means of G6 (Dexcom, San Diego, CA) sensors for a time span of 120 days. Glycated hemoglobin laboratory assays were performed during the concluding follow-up visits. Data were then analyzed to derive estimates of assay results, taken as the gold standard.

RESULTS

Bland-Altman (BA) plots show that smart interpolation to patch missing data and a wise choice of interstitial glucose (IG) weighting function, besides a proper mean interstitial glucose (MIG) to HbA1c regression equation, improve HbA1c estimation quality with respect to methods relying on MIG alone. A decrease in the BA plot-related variance of differences with respect to the gold standard confirms the improvement. Wilcoxon signed-rank tests on the bias-compensated mean squared error (MSE) with respect to conventional MIG-based methods show that the improvement is statistically significant with a confidence level better than 95% (P = .0179).

CONCLUSIONS

Improved HbA1c estimation methods result in better HbA1c prediction quality with respect to those based on MIG alone, thus providing quick, but still relatively accurate feedback to diabetologists. They alleviate the discordances reported in literature and, with further improvements, may become a viable complement/alternative to HbA1c assays.

Psychological Characteristics and Goals of Caregivers Choosing Continuous Glucose Monitoring for Children With Type 1 Diabetes

BACKGROUND

Continuous glucose monitoring (CGM) can improve glycemic outcomes in pediatric type 1 diabetes management. However, its impact on the psychosocial functioning of caregivers is less well described. The objectives of this pilot study were to explore caregiver reasons for adding CGM to their child's type 1 diabetes management, parental psychosocial function before initiating CGM, and the relationship between the two.

METHODS

Thirty-two families with a child with type 1 diabetes from Rainbow Babies and Children's Hospital diabetes clinics who were initiating CGM were recruited over 3 months. Before CGM initiation, the caregivers completed the Fear of Hypoglycemia Scale, State-Trait Anxiety Inventory, Problem Areas in Diabetes Scale, and a questionnaire assessing their primary reason for starting CGM. Participant characteristics and questionnaire results were summarized with descriptive statistics. Participants were grouped by reason for starting CGM, and results were compared among groups using ANOVA and reporting the global F test.

RESULTS

Fifty percent of respondents indicated that they were starting CGM to optimize glycemic control. The majority of parents (71.8%) expressed worry about helplessness during a hypoglycemic episode. There were no statistically significant differences in patient characteristics or questionnaire results between groups. Forty-three percent of participating families started using CGM during the study's 8-month follow-up period. The main reason (64%) for not starting CGM was not having the chance to start the process of obtaining a CGM system. There were no statistically significant differences between children who did and did not start CGM.

CONCLUSION

Caregivers have different reasons for starting CGM for their child with type 1 diabetes. Further studies are needed to understand whether these reasons are related to differences in psychosocial functioning. Despite interest in starting CGM, there remain barriers to implementation.

Technological Ecological Momentary Assessment Tools to Study Type 1 Diabetes in Youth: Viewpoint of Methodologies

Type 1 diabetes (T1D) is one of the most common chronic childhood diseases, and its prevalence is rapidly increasing. The management of glucose in T1D is challenging, as youth must consider a myriad of factors when making diabetes care decisions. This task often leads to significant hyperglycemia, hypoglycemia, and glucose variability throughout the day, which have been associated with short- and long-term medical complications. At present, most of what is known about each of these complications and the health behaviors that may lead to them have been uncovered in the clinical setting or in laboratory-based research. However, the tools often used in these settings are limited in their ability to capture the dynamic behaviors, feelings, and physiological changes associated with T1D that fluctuate from moment to moment throughout the day. A better understanding of T1D in daily life could potentially aid in the development of interventions to improve diabetes care and mitigate the negative medical consequences associated with it. Therefore, there is a need to measure repeated, real-time, and real-world features of this disease in youth. This approach is known as ecological momentary assessment (EMA), and it has considerable advantages to in-lab research. Thus, this viewpoint aims to describe EMA tools that have been used to collect data in the daily lives of youth with T1D and discuss studies that explored the nuances of T1D in daily life using these methods. This viewpoint focuses on the following EMA methods: continuous glucose monitoring, actigraphy, ambulatory blood pressure monitoring, personal digital assistants, smartphones, and phone-based systems. The viewpoint also discusses the benefits of using EMA methods to collect important data that might not otherwise be collected in the laboratory and the limitations of each tool, future directions of the field, and possible clinical implications for their use.

Feasibility of the Web-Based Intervention Designed to Educate and Improve Adherence Through Learning to Use Continuous Glucose Monitor (IDEAL CGM) Training and Follow-Up Support Intervention: Randomized Controlled Pilot Study

Background

Proper training and follow-up for patients new to continuous glucose monitor (CGM) use are required to maintain adherence and achieve diabetes-related outcomes. However, CGM training is hampered by the lack of evidence-based standards and poor reimbursement. We hypothesized that web-based CGM training and education would be effective and could be provided with minimal burden to the health care team.

Objective

The aim of this study was to perform a pilot feasibility study testing a theory-driven, web-based intervention designed to provide extended training and follow-up support to adolescents and young adults newly implementing CGM and to describe CGM adherence, glycemic control, and CGM-specific psychosocial measures before and after the intervention.

Methods

The “Intervention Designed to Educate and improve Adherence through Learning to use CGM (IDEAL CGM)” web-based training intervention was based on supporting literature and theoretical concepts adapted from the health belief model and social cognitive theory. Patients new to CGM, who were aged 15-24 years with type 1 diabetes for more than 6 months were recruited from within a public university’s endocrinology clinic. Participants were randomized to enhanced standard care or enhanced standard care plus the IDEAL CGM intervention using a 1:3 randomization scheme. Hemoglobin A_1c levels and psychosocial measures were assessed at baseline and 3 months after start of the intervention.

Results

Ten eligible subjects were approached for recruitment and 8 were randomized. Within the IDEAL CGM group, 4 of the 6 participants received exposure to the web-based training. Half of the participants completed at least 5 of the 7 modules; however, dosage of the intervention and level of engagement varied widely among the participants. This study provided proof of concept for use of a web-based intervention to deliver follow-up CGM training and support. However, revisions to the intervention are needed in order to improve engagement and determine feasibility.

Conclusions

This pilot study underscores the importance of continued research efforts to optimize the use of web-based intervention tools for their potential to improve adherence and glycemic control and the psychosocial impact of the use of diabetes technologies without adding significant burden to the health care team. Enhancements should be made to the intervention to increase engagement, maximize responsiveness, and ensure attainment of the skills necessary to achieve consistent use and improvements in glycemic control prior to the design of a larger well-powered clinical trial to establish feasibility.

Trial Registration

ClinicalTrials.gov NCT03367351, https://clinicaltrials.gov/ct2/show/NCT03367351.

Evaluation of Patient Willingness to Adopt Remote Digital Monitoring for Diabetes Management

Importance

Patients will decide whether to adopt remote digital monitoring (RDM) for diabetes by weighing its health benefits against the inconvenience it may cause.

Objective

To identify the minimum effectiveness patients report they require to adopt 36 different RDM scenarios.

Design, Setting, and Participants

This survey study was conducted among adults with type 1 or type 2 diabetes living in 30 countries from February to July 2019.

Exposures

Survey participants assessed 3 randomly selected scenarios from a total of 36. Scenarios described different combinations of digital monitoring tools (glucose, physical activity, food monitoring), duration and feedback loops (feedback in consultation vs real-time telefeedback by a health care professional or by artificial intelligence), and data handling modalities (by a public vs private company), reflecting different degrees of RDM intrusiveness in patients' personal lives.

Main Outcomes and Measures

Participants assessed the minimum effectiveness for 2 diabetes-related outcomes (reducing hypoglycemic episodes and preventing ophthalmologic complications) for which they would adopt each RDM (from much less effective to much more effective than their current monitoring).

Results

Of 1577 individuals who consented to participate, 1010 (64%; 572 [57%] women, median [interquartile range] age, 51 [37-63] years, 524 [52%] with type 1 diabetes) assessed at least 1 vignette. Overall, 2860 vignette assessments were collected. In 1025 vignette assessments (36%), participants would adopt RDM only if it was much more effective at reducing hypoglycemic episodes compared with their current monitoring; in 1835 assessments (65%), participants would adopt RDM if was just as or somewhat more effective. The main factors associated with required effectiveness were food monitoring (β = 0.32; SE, 0.12; P = .009), real-time telefeedback by a health care professional (β = 0.49; SE, 0.15; P = .001), and perceived intrusiveness (β = 0.36; SE, 0.06; P < .001). Minimum required effectiveness varied among participants; 34 of 36 RDM scenarios (94%) were simultaneously required to be just as or less effective by at least 25% of participants and much more effective by at least 25% of participants. Results were similar for participant assessments of scenarios regarding the prevention of ophthalmologic complications.

Conclusions and Relevance

The findings of this study suggest that patients require greater health benefits to adopt more intrusive RDM modalities, food monitoring, and real-time feedback by a health care professional. Patient monitoring devices should be designed to be minimally intrusive. The variability in patients' requirements points to a need for shared decision-making.

Has subsidized continuous glucose monitoring improved outcomes in pediatric diabetes?

INTRODUCTION

In 2017, the Australian Federal Government fully subsidized continuous glucose monitoring (CGM) devices for patients under 21 years of age with T1D with the aim of reducing rates of severe hypoglycaemia (SH) and improving metabolic control. The aim of this study was to reports on metabolic outcomes in youth from a single tertiary centre.

METHODS

The study design was observational. Data were obtained on youth who commenced CGM between May 2017 and December 2019.

RESULTS

Three hundred and forty one youth who commenced CGM and had clinical outcome data for a minimum of 4 months. 301, 261, 216, 172, and 125 had outcome data out to 8, 12, 16, 20, and 24 months, respectively. Cessation occurred between 27.9% and 32.8% of patients 12 to 24 months after CGM commencement. HbA1c did not change in patients who continued to use CGM. In the 12 months prior to starting CGM the rate of severe hypoglycaemia events were 5.0 per 100 patient years. The rates of severe hypoglycaemia in those continuing to use CGM at 4, 8, 12, 16, 20, and 24 months, were 5.2, 5.1, 1.6, 6.1, 2.4, and 0 per 100 patient years, respectively.

DISCUSSION

Our experience of patients either ceasing or underusing CGM is less than reported in other cohorts but is nonetheless still high. There may have been a reduction in rates of severe hypoglycaemia over the 24 months follow up period; however, the absolute numbers of events were so low as to preclude meaningful statistical analysis.

Parental Experiences of Continuous Glucose Monitoring in Danish Children with Type 1 Diabetes Mellitus

PURPOSE

To explore parents 'experience of having a child aged 4-9 years with type 1 diabetes mellitus (T1DM) using continuous glucose monitor (CGM).

DESIGN AND METHODS

The study was a qualitative study. Twelve families were recruited for individual or dyadic interviews through purposeful and convenience sampling procedures.

RESULTS

Thematic analysis generated three main themes: 1) Living in the context of the unpredictability of diabetes 2) Establishing a sense of control and security with the CGM 3) Learning to use and trust the CGM and educating other caregivers.

CONCLUSIONS

Living in the context of the unpredictability of T1DM causes a loss of stability and control as T1DM pervades family life and transforms everyday routines. CGM use seems to increase opportunities for other family activities, as it provides parents with a sense of control and moderates the pervasiveness of T1DM. Yet the parents have to learn how to trust and use the CGM and take on the burdensome task of training and trusting other caregivers.

PRACTICE IMPLICATIONS

The CGM is used as an integral part of T1DM care in everyday life. Therefore, it should be accessible to families. Health-care professionals should be aware of how to assist parents with how to use and trust the CGM. Furthermore, parents may need help and support in educating other caregivers on how to use the CGM. This could be done through teaching sessions, written materials and recorded demonstrations of CGM use.

Executive Functions and Adherence to Continuous Glucose Monitoring in Children and Adolescents with Type 1 Diabetes

Background: Continuous glucose monitoring (CGM) has a beneficial impact on diabetes control; however, its utilization within people with diabetes remains low. The success of CGM requires cluster of cognitive skills and executive functions (EF). We speculated that participants with high EF would be more adherent to CGM use. Materials and Methods: The study population included 85 children and adolescents between 5 and 18 years old being followed for type 1 diabetes. Participants and their parents completed three questionnaires-"Behavior Rating Inventory of Executive Function" (BRIEF), CGM satisfaction, and a questionnaire assessing reasons for discontinuing CGM use. Results: Sixty-one participants used CGM on a regular basis and 24 discontinued use. Adherent participants were significantly younger than participants with nonadherence to CGM (P = 0.011). No significant differences were found between gender, diabetes duration, or HbA1c. Females adhering to CGM had a significantly higher "organization of environment" skill than those with nonadherence to CGM (P = 0.023). Also, adherent participants older than 14 years had a higher "organization of environment" skill than participants with nonadherence to CGM (P = 0.032). No difference was found between the groups in other EF domains. Alarm fatigue was found to be the main reason for discontinuing CGM. Conclusions: Given the interplay between CGM adherence and EF, it is recommended that people with diabetes should receive training by a multidisciplinary team, including psychological counseling, before CGM use and thus preparing them to cope with the demands of CGM and to avoid false expectations.

Trust in hybrid closed loop among people with diabetes: Perspectives of experienced system users

Automated closed loop systems will greatly change type 1 diabetes management; user trust will be essential for acceptance of this new technology. This qualitative study explored trust in 32 individuals following a hybrid closed loop trial. Participants described how context-, system-, and person-level factors influenced their trust in the system. Participants attempted to override the system when they lacked trust, while trusting the system decreased self-management burdens and decreased stress. Findings highlight considerations for fostering trust in closed loop systems. Systems may be able to engage users by offering varying levels of controls to match trust preferences.

Decisions in the Psychology of Glucose Monitoring

This commentary aims to discuss the parallels between nonadherence to continuous glucose level monitoring and nonadherence to medication in people with diabetes and to investigate specific reasons for the difficulties involved in glucose monitoring. To this end, examples are given from both continuous and discontinuous glucose monitoring (CGM and SMBG, respectively).

Hydrogel Microfilaments toward Intradermal Health Monitoring

Digital health promises a paradigm shift for medicine where biomarkers in individuals are continuously monitored to improve diagnosis and treatment of disease. To that end, a technology for minimally invasive quantification of endogenous analytes in bodily fluids will be required. Here, we describe a strategy for designing and fabricating hydrogel microfilaments that can penetrate the skin while allowing for optical fluorescence sensing. The polyacrylamide formulation was selected to provide high elastic modulus in the dehydrated state and optical transparency in the hydrated state. The microfilaments can be covalently tethered to a fluorescent aptamer to enable functional sensing. The microfilament array can penetrate the skin with low pain and without breaking, contact the dermal interstitial fluid, and be easily removed from the skin. In the future, hydrogel microfilaments could be integrated with a wearable fluorometer to serve as a platform for continuous, minimally invasive monitoring of intradermal biomarkers.

Human Factors Associated with Continuous Glucose Monitor Use in Patients with Diabetes: A Systematic Review

Consistent continuous glucose monitor (CGM) use is associated with substantial improvements in glycemic control, yet the uptake and continued use of these technologies remains low. This systematic review aims to identify and summarize the state of science on human factors and their association with CGM use to inform training methods and best practices that support adherence to CGM use and automated insulin delivery systems. A literature search was conducted in PubMed, CINAHL, The Cochrane Library, and PsychInfo databases using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify studies that reported psychological human factors related to CGM or sensor-augmented pump use in patients with type 1 diabetes. In total, 389 records were identified through our database search and 26 studies published between 2010 and 2017 were included. Articles underwent quality appraisal using the Effective Public Health Practice Project Quality Assessment Tool and were categorized according to study outcomes. Identified human factors with a potential association with CGM use were treatment satisfaction, quality of life, emotional distress, and self-efficacy. Eight patient-reported barriers to CGM use were identified as a subcomponent of satisfaction. To date, studies of human factors associated with CGM use generally lack standardized measures and sufficient methodological rigor necessary to establish causation. A more robust understanding of how identified human factors influence CGM use is necessary. Future studies should test interventions that target human factors to improve consistency of use and establish best practices for enhancing patients' experience and acceptance of these technologies, especially within adolescents and young adults.

Continuous glucose monitoring in adults with type 1 diabetes: A balance between benefits and barriers: A critical incident study

AIMS AND OBJECTIVES

To describe positively and negatively perceived situations experienced by adults with type 1 diabetes using continuous glucose monitoring and the actions they take to deal with these situations.

BACKGROUND

Real-time continuous glucose monitoring has been shown to improve glycaemic control and reduce hypoglycaemia. Although many patients with type 1 diabetes report great benefits when using continuous glucose monitoring, a substantial number discontinue using the device. Little is known about the different situations and experiences with the daily use of continuous glucose monitoring that contribute to such differences.

DESIGN

A descriptive design based on the critical incident technique was used. The study complied with the Consolidated Criteria for Reporting Qualitative Research (COREQ) (see File S1).

METHODS

Individual interviews were conducted with a purposive sample of 23 adults with type 1 diabetes, including current and former users of continuous glucose monitoring from four different outpatient clinics.

RESULTS

The participants described that they felt that the use of continuous glucose monitoring was a balance between benefits and barriers, and how, through their actions, they tried to adapt their use of continuous glucose monitoring to fit their lifestyles. Various life events affected and altered the balance between benefits and barriers and thus affected their use of continuous glucose monitoring.

CONCLUSIONS

Continuous glucose monitoring is perceived as an effective and important tool in the self-management of diabetes type 1. It enables a better everyday life and increased satisfaction with treatment. At the same time, the use of continuous glucose monitoring can be both demanding and challenging.

RELEVANCE TO CLINICAL PRACTICE

Understanding the complex interplay between perceived benefits, treatment burden and adherence to continuous glucose monitoring use is important for nurses engaged in diabetes care. Education and support regarding the use of continuous glucose monitoring must be based on the understanding and perspectives of the patient to alleviate stress and barriers and enhance self-efficacy. As the use of continuous glucose monitoring can change over time, this must be a continuous process beyond initial training.

Real-World Hypoglycemia Avoidance with a Continuous Glucose Monitoring System's Predictive Low Glucose Alert

BACKGROUND

Programmable and fixed auditory and/or vibratory threshold alerts are essential features of real-time continuous glucose monitoring (rtCGM) systems that provide users time to intervene before the onset of clinical hypoglycemia or hyperglycemia. A sixth-generation rtCGM system from Dexcom, Inc. (G6) includes a new alert that is triggered when an algorithm predicts that an estimated glucose value ≤55 mg/dL will occur within 20 min, allowing users more time to act to avoid hypoglycemia. We examined whether this predictive low glucose alert provided added benefit to traditional low threshold alerts.

METHODS

We analyzed glucose values from an anonymized sample of 1424 patients who transitioned to G6 from the preceding fifth-generation system (G5) with no predictive alert. Users with the low threshold alert setting of 70 or 80 mg/dL were evaluated separately. Receiver users, those who disabled the predictive low glucose alert, or those with <30 days of data immediately before or after the transition to G6 were excluded.

RESULTS

Percent time <54, ≤55, <70, and >250 mg/dL fell significantly after the transition to G6, independent of low threshold alert setting. Time in range improved for G6 users with a low threshold alert setting of 70 mg/dL.

CONCLUSIONS

Advance warning provided by predictive low glucose alerts may further reduce hypoglycemia among rtCGM-experienced users.

Performance of a Factory-Calibrated, Real-Time Continuous Glucose Monitoring System in Pediatric Participants With Type 1 Diabetes

BACKGROUND

The perceived value and consistent use of continuous glucose monitoring (CGM) systems depends in part on their accuracy. We assessed the performance of a sixth-generation CGM system (Dexcom G6) in children and adolescents.

METHODS

Forty-nine participants (6-17 years of age, mean ± SD of 13.5 ± 3.3 years), all with type 1 diabetes, enrolled and data were available from 37. Each participant wore 1 sensor for up to 10 days and was asked to undergo an in-clinic visit lasting 6-12 hours for frequent blood glucose (BG) sample testing on one of the sensor wear days. Estimated glucose values (EGVs) from the G6 system were compared with venous BG values measured with a laboratory reference instrument (YSI).

RESULTS

The overall mean absolute relative difference (MARD) for 1387 EGV-YSI pairs was 7.7%, and the overall percentage of EGVs within 20% or 20 mg/dL of the YSI reference value (for YSI > or ⩽100 mg/dL, respectively, the "%20/20") was 96.2%. The %20/20 was 92.1% on Day 1 and 91.0% on Day 10 of sensor wear. For EGVs <70 mg/dL, 92.6% of the YSI values were within 20 mg/dL and for EGVs >250 mg/dL, 100% of the YSI values were within 20%. Differences between EGVs and YSI values in over 99.9% of the pairs posed no or only slight clinical risk as evaluated by surveillance error grid analysis.

CONCLUSIONS

The accuracy of the G6 CGM system in pediatrics may encourage consistent use of the system and contribute to improved glycemic outcomes in this population.

Evaluation of flash glucose monitoring after long-term use: A pediatric survey

AIMS

To understand the opinions of children with type 1 diabetes about their everyday use of flash glucose monitoring. (FGM).

METHODS

Children with type 1 diabetes using the FreeStyle Libre® FGM system and/or their parents were surveyed in several French medical centers between December 2016 and June 2017, regardless of their treatment regimen and metabolic control.

RESULTS

Of the 347 patients recruited, 79.5% had been using the sensor for more than three months (average usage time: 285 days). The main reported motivations for initiating this type of monitoring were to avoid finger prick pain (for 85.9% of patients) and to allow parents to check nocturnal glucose levels (60.8%). Two-thirds of respondents experienced difficulties, mainly the sensor falling off (47.6%), measurement discrepancies (25.1%) and cutaneous reactions (22.2%); 89.5% changed their habits: 70.6% took more scans, 37.2% corrected their hyperglycemia more promptly, and 37.5% used trends to adjust their insulin dosage. About one-third of the study group (35.1%) experienced lower HbA1c levels, and two thirds (67.1%) were satisfied with the device.

CONCLUSIONS

Our results show that FGM is a widely accepted option for self-monitoring diabetes, but that specific training is required to improve its use for insulin dosage adjustment and metabolic results.

Accuracy of a Fourth-Generation Continuous Glucose Monitoring System in Children and Adolescents with Type 1 Diabetes

BACKGROUND

This study evaluated the safety and performance of the Guardian™ continuous glucose monitoring (CGM) system in children and adolescents with type 1 diabetes (T1D).

MATERIALS AND METHODS

Subjects 2-18 years of age (mean ± standard deviation [SD] 13.1 ± 3.9 years) with T1D and duration of diagnosis ≥1 year were enrolled at 11 sites in the United States and wore two Guardian Sensor 3 sensors in the abdomen and/or buttock. Sensors were connected to a transmitter paired with either a Guardian Connect system (i.e., mobile device with software application allowing display of sensor glucose [SG] values) or a Guardian Link 3 transmitter used as a Glucose Sensor Recorder (GSR). There were 145 participants who underwent a 6-h in-clinic frequent sample testing (FST) on day 1 (n = 54), day 3 (n = 48), or day 7 (n = 43) postsensor insertion. During FST, SG values were compared with a Yellow Springs Instrument (YSI) plasma reference every 5-15 min (n = 124, 7-18 years of age; n = 2, 2-6 years of age), or to a self-monitoring of blood glucose (SMBG) reference every 5-30 min (n = 19, 2-6 years of age).

RESULTS

The overall mean absolute relative difference (ARD ± SD) between SG and reference values (YSI or SMBG) when calibrating approximately every 12 h, was 10.9% ± 10.7% (3102 paired points) for sensors communicating with the Guardian Connect system and 11.1% ± 10.6% (2624 paired points) for sensors connected to the GSR. The overall percentage of SG values within ±20% of reference values >80 mg/dL or within 20 mg/dL of reference values ≤80 mg/dL was 87.8% for the Guardian Connect system and 86.7% for the GSR, respectively. There was one device-related adverse event of contact dermatitis, but no serious device-related adverse events.

CONCLUSIONS

The Guardian CGM system demonstrated good accuracy in children and adolescents. These findings support its use in sensor-integrated insulin pump platforms, as well as a standalone technology, for managing diabetes in pediatric populations.

Continuous Glucose Monitoring (CGM) or Blood Glucose Monitoring (BGM): Interactions and Implications

At the 2017 10th annual International Conference on Advanced Technologies and Treatments for Diabetes (ATTD) in Paris, France, four speakers presented their perspectives on the roles of continuous glucose monitoring (CGM) and of blood glucose monitoring (BGM) in patient management within one symposium. These presentations included discussions of the differences in the accuracy of CGM and BGM, a clinical perspective on the physiological reasons behind differences in CGM and BGM values, and an overview of the impact of variations in device accuracy on patients with diabetes. Subsequently a short summary of these presentations is given, highlighting the value of good accuracy of BGM or CGM systems and the ongoing need for standardization. The important role of both BGM and CGM in patient management was a theme across all presentations.

Healthcare Resource Waste Associated with Patient Nonadherence and Early Discontinuation of Traditional Continuous Glucose Monitoring in Real-World Settings: A Multicountry Analysis

BACKGROUND

Traditional continuous glucose monitoring (CGM) provides detailed information on glucose patterns and trends to inform daily diabetes management decisions, which is particularly beneficial for patients with a history of hypoglycemia unawareness. However, a high level of patient adherence (≥70%) is required to achieve clinical benefits. The aim of this study was to assess the impact of real-world patient nonadherence and early discontinuation on healthcare resource use.

METHODS

A cost calculator was designed to evaluate monthly healthcare resource waste within the first year of traditional CGM initiation by combining estimates of real-world nonadherence and early discontinuation from the literature with the wholesale acquisition costs of the current technology in the United States (for a commercial payer and for Medicare), or its equivalent in Sweden, Germany, or the Netherlands.

RESULTS

Based on an early discontinuation rate of 27% and nonadherence rates of 13.9%-31.1% over the 12 months following initiation, the healthcare resource waste associated with nonadherence and early discontinuation was $220,289 and $21,775, respectively, for every 100 patients initiating CGM in the U.S. commercial payer scenario. In the Medicare scenario, the corresponding figures were $72,648 and $5,675, respectively. In both scenarios, nonadherence and early discontinuation accounted for ∼24% of resources being wasted within the first year of CGM initiation. Similar results were observed using the local costs in the other countries analyzed.

CONCLUSIONS

The healthcare resource waste associated with traditional CGM nonadherence and early discontinuation warrants deliberate consideration when selecting suitable patients for this technology.

Use of Flash Glucose-Sensing Technology for 12 months as a Replacement for Blood Glucose Monitoring in Insulin-treated Type 2 Diabetes

INTRODUCTION

Published evaluations of sensor glucose monitoring use in insulin treated type 2 diabetes are limited. The aim of this study was to assess the impact of flash glucose-sensing technology as a replacement for self-monitoring of blood glucose (SMBG) over a 12-month period in participants with type 2 diabetes who were on intensive insulin therapy.

METHODS

An open-label, randomized, controlled study in adults with type 2 diabetes on intensive insulin therapy from 26 European diabetes centers aimed at assessing flash glucose sensing technology was conducted. Participants (N = 224) were randomized (1:2 respectively) to a control group (n = 75) that used SMBG (FreeStyle Lite™) or to an intervention group (n = 149) which used sensor glucose data (FreeStyle Libre™ Flash Glucose Monitoring System) for self-management over 6 months. All intervention group participants who completed the 6-month treatment phase continued into an additional 6-month open-access phase.

RESULTS

A total of 139 intervention participants completed the 6-month treatment phase and continued into the open-access phase. At 12 months (end of open-access period), time in hypoglycemia [sensor glucose <3.9 mmol/L (70 mg/dL)] was reduced by 50% compared to baseline [-0.70 ± 1.85/24 h (mean ± standard deviation); p = 0.0002]. Nocturnal hypoglycemia [2300 to 0600 hours, <3.9 mmol/L (70 mg/dL)] was reduced by 52%; p = 0.0002. There was no change in time in range [sensor glucose 3.9-10.0 mmol/L (70-180 mg/dL)]. SMBG testing fell from a mean of 3.9 (median 3.9) times/day at baseline to 0.2 (0.0), with an average frequency of sensor scanning of 7.1 (5.7) times/day at 12 months, and mean sensor utilization was 83.6 ± 13.8% (median 88.3%) during the open-access phase. During this 6-month extension period no device-related serious adverse events were reported. Nine participants reported 16 instances of device-related adverse events (e.g. infection, allergy) and 28 participants (20.1%) experienced 134 occurrences of anticipated skin symptoms/sensor-insertion events expected with device use (e.g. erythema, itching and rash).

CONCLUSION

The use of flash glucose-sensing technology for glycemic management in individuals with type 2 diabetes treated by intensive insulin therapy over 12 months was associated with a sustained reduction in hypoglycemia and safely and effectively replaced SMBG.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02082184.

Continuous Glucose Monitoring (CGM) Adherence in Youth With Type 1 Diabetes: Associations With Biomedical and Psychosocial Variables

BACKGROUND

Continuous glucose monitoring (CGM) remains underutilized in youth with type 1 diabetes (T1D). There is a need to investigate factors associated with CGM use.

METHOD

In 61 T1D youth, CGM use was ascertained by downloads reflecting the 4-week periods preceding 3- and 6-month study visits. Demographic and clinical data were obtained from chart review and interview. Youth and parents completed validated psychosocial surveys at baseline and 6 months.

RESULTS

Youth (52% male, 93% Caucasian, 80% pump treated) were 12.7 ± 2.9 years old, with T1D for 6.3 ± 3.8 years; mean A1c was 7.9 ± 0.9%. Mean CGM use was 4.1 ± 2.1 days/week (median = 4.8) at 3 months and 3.4 ± 2.3 days/week (median = 3.9) at 6 months. At 3 and 6 months, 15% and 20% of youth, respectively, had stopped using CGM. At 6 months, youth using CGM 6-7 days/week had more frequent BG monitoring ( P = .05), less insulin omission ( P = .02), and greater probability of A1c < 7.5% ( P = .01) than youth using CGM less often. Youth using CGM 6-7 days/week consistently over the 6 months demonstrated lower A1c at 3 months compared to baseline ( P = .03) and the improvement was sustained at 6 months ( P = .5, 3 vs 6 months); youth using CGM less often had no significant A1c change. Baseline BG monitoring ≥8 times/day or A1c within target (<7.5%) predicted greater CGM use (6-7 days/week) at 6 months (OR = 4.6, P = .02). There was no deterioration of psychosocial functioning with CGM use.

CONCLUSIONS

Consistent and durable CGM use in youth with T1D is associated with treatment adherence and improved glycemic control without increasing psychosocial distress.

Optimal Use of Diabetes Devices: Clinician Perspectives on Barriers and Adherence to Device Use

BACKGROUND

Insulin pumps and continuous glucose monitors (CGM) can improve glycemic control for individuals with type 1 diabetes (T1D). Device uptake rates continue to show room for improvement, and consistent adherence is needed to achieve better outcomes. Diabetes health care providers have important roles to play in promoting device use and adherence.

METHODS

We surveyed 209 clinicians who treat people with type 1 diabetes to examine perceptions of barriers to device uptake, attitudes toward diabetes technology, and resources needed for clinicians to improve device uptake. We compared findings with our survey of adults with T1D.

RESULTS

Younger clinicians treated more patients using insulin pumps ( r = -.26, P < .001) and CGM ( r = -.14, P = .02), and had more positive attitudes about diabetes technology ( r = -.23, P = .001). The most frequently endorsed modifiable barriers were perceptions that patients dislike having the device on their body (73% pump; 63% CGM), dislike the alarms (61% CGM), and do not understand what to do with device information or features (40% pump; 46% CGM). Clinicians wanted lower cost and better insurance coverage for their patients, and they recommended counseling and education to help address barriers and improve adherence to devices.

CONCLUSION

Clinicians perceive many barriers to their patients initiating and adhering to diabetes devices. Findings highlight opportunities for intervention to improve clinician-patient communication around device barriers to help address them.

Recruitment Into a Pediatric Continuous Glucose Monitoring RCT

BACKGROUND

The purpose was to identify patient/family characteristics and recruitment process characteristics associated with the decision to participate in a 2-year continuous glucose monitoring (CGM) RCT for youth with type 1 diabetes and their families.

METHOD

Study staff approached patients who were conditionally eligible according to medical record review or referred by a provider. We categorized families according to participation decision (agree vs decline) and timing of decision (day of approach vs later ["thinkers"]).

RESULTS

Over 18 months, we approached 456 eligible patients; 19% agreed on the day of approach, 10% agreed later, 42% declined on the day of approach, and 30% declined later. Agreers were younger ( P = .002), had shorter diabetes duration ( P = .0003), had a lower insulin dose ( P = .02), checked blood glucose levels more often ( P = .002), and were more likely to use pump therapy ( P = .009) than decliners. Patients/families were more likely to agree in fall/winter (41%) than spring/summer (19%, P < .0001). Of decliners, 50% cited no interest in CGM as the reason for nonparticipation. Among thinkers, 49% of patients who made a decision within 2 weeks of being approached agreed; only 15% of thinkers who made a decision >2 weeks after being approached agreed to participate ( P < .0001).

CONCLUSIONS

Recruitment is a critical and often challenging phase of clinical trials. Recruitment to pediatric CGM studies may be especially challenging due to youths' reluctance to use CGM. These data provide an opportunity to better understand and possibly optimize recruitment into future pediatric CGM studies and other studies of advanced diabetes technologies.

Psychological Reactions Associated With Continuous Glucose Monitoring in Youth

Glucose monitoring is prerequisite to all other diabetes self-care behaviors and helps patients to reduce their risk for diabetes-related complications due to elevated glycemia. Because of the amount of information available and the ability to deliver glucose results in real-time, continuous glucose monitoring (CGM) has the ability to improve on self-monitoring blood glucose. However, epidemiologic data demonstrate slow uptake of CGM by patients, especially among youth. Several new diabetes therapies rely on CGM for feedback on patients' glucose levels to optimize treatment (eg, the low-glucose suspend insulin pump) and there are new technologies currently in development that will also need this information to work (eg, the artificial pancreas). To help patients to realize the potential benefits of these new treatments, it is essential to explore patients' psychological and behavioral reactions to CGM and then target device enhancements and/or the development of behavioral therapies to minimize negative reactions and to improve patients' CGM adoption rates. Limited research is available examining the psychological and behavioral reactions of CGM use in youth exclusively, but there are more studies examining these reactions in mixed samples of youth, parents, and adults. The purpose of this review is to summarize the available literature examining psychological and behavioral reactions to CGM use in young people with diabetes and to highlight how the results of past and future studies can inform device updates and/or behavioral intervention development to minimize barriers.

Technology Use in Transition-Age Patients With Type 1 Diabetes: Reality and Promises

Youth with chronic illnesses have the greatest risk for a decline in their health management during transition-age. Because of this demonstrated and well-known issue, research has focused on how to improve the transition of care process. Despite the increasing number of technological devices on the market and the advances in telemedicine modalities available to patients with type 1 diabetes (T1D), the utilization of technology is still suboptimal among patients of transition-age (ages 13-25). This article reviews the available resources, patterns of use in transition-age youth, and explores opportunities to advance technology use in transitioning patients with T1D from pediatric to adult care.

Improved Accuracy of Continuous Glucose Monitoring Systems in Pediatric Patients with Diabetes Mellitus: Results from Two Studies

OBJECTIVE

This study was designed to evaluate accuracy, performance, and safety of the Dexcom (San Diego, CA) G4(®) Platinum continuous glucose monitoring (CGM) system (G4P) compared with the Dexcom G4 Platinum with Software 505 algorithm (SW505) when used as adjunctive management to blood glucose (BG) monitoring over a 7-day period in youth, 2-17 years of age, with diabetes.

RESEARCH DESIGN AND METHODS

Youth wore either one or two sensors placed on the abdomen or upper buttocks for 7 days, calibrating the device twice daily with a uniform BG meter. Participants had one in-clinic session on Day 1, 4, or 7, during which fingerstick BG measurements (self-monitoring of blood glucose [SMBG]) were obtained every 30 ± 5 min for comparison with CGM, and in youth 6-17 years of age, reference YSI glucose measurements were obtained from arterialized venous blood collected every 15 ± 5 min for comparison with CGM. The sensor was removed by the participant/family after 7 days.

RESULTS

In comparison of 2,922 temporally paired points of CGM with the reference YSI measurement for G4P and 2,262 paired points for SW505, the mean absolute relative difference (MARD) was 17% for G4P versus 10% for SW505 (P < 0.0001). In comparison of 16,318 temporally paired points of CGM with SMBG for G4P and 4,264 paired points for SW505, MARD was 15% for G4P versus 13% for SW505 (P < 0.0001). Similarly, error grid analyses indicated superior performance with SW505 compared with G4P in comparison of CGM with YSI and CGM with SMBG results, with greater percentages of SW505 results falling within error grid Zone A or the combined Zones A plus B. There were no serious adverse events or device-related serious adverse events for either the G4P or the SW505, and there was no sensor breakoff.

CONCLUSIONS

The updated algorithm offers substantial improvements in accuracy and performance in pediatric patients with diabetes. Use of CGM with improved performance has potential to increase glucose time in range and improve glycemic outcomes for youth.

Clinical Efficacy of Two Different Methods to Initiate Sensor-Augmented Insulin Pumps: A Randomized Controlled Trial

Aim. To analyze clinical effect of a novel approach to initiate sensor-augmented insulin pumps in type 1 diabetes mellitus (T1DM) patients through early real-time continuous glucose monitoring (RT-CGM) initiation. Methods. A 26-week pilot study with T1DM subjects randomized (1 : 1) to start RT-CGM three weeks before continuous subcutaneous insulin infusion (CGM pre-CSII) or adding RT-CGM three weeks after continuous subcutaneous insulin infusion (CGM post-CSII). Results. Twenty-two patients were enrolled with a mean age of 36.6 yr. (range 19-59 yr.) and T1DM duration of 16.8 ± 10.6 yr. Higher adherence in CGM pre-CSII patients was confirmed at study end (84.6 ± 11.1% versus 64.0 ± 25.4%; P = 0.01). The two intervention groups had similar HbA_1c reduction at study end of -0.6% (P = 0.9). Hypoglycemic event frequency reduction was observed from baseline to study end only in CGM pre-CSII group (mean difference in change, -6.3%; 95% confidence interval, -12.0 to -0.5; P = 0.04). Moreover, no severe hypoglycemia was detected among CGM pre-CSII subjects during the study follow-up (0.0 ± 0.0 events versus 0.63 ± 1.0 events; P = 0.03). CGM pre-CSII patients showed better satisfaction than CGM post-CSII patients at the end of the study (27.3 ± 9.3 versus 32.9 ± 7.2; P = 0.04). Conclusions. CGM pre-CSII is a novel approach to improve glycemic control and satisfaction in type 1 diabetes sensor-augmented pump treated patients.

Diabetes Device Interoperability for Improved Diabetes Management

Scientific and technological advancements have led to the increasing availability and use of sophisticated devices for diabetes management, with corresponding improvements in public health. These devices are often capable of sharing data with a few other specific devices but are generally not broadly interoperable; they cannot work together with a wide variety of other devices. As a result of limited interoperability, benefits of modern diabetes devices and potential for development of innovative new diabetes technologies are not being fully realized. Here we discuss diabetes device interoperability in general, then focus on 4 examples that show how diabetes management could benefit from enhanced interoperability: remote monitoring and data sharing, integrating data from multiple devices to better inform diabetes management strategies, device consolidation, and artificial pancreas development.

Continuous glucose monitoring in people with diabetes: the randomized controlled Glucose Level Awareness in Diabetes Study (GLADIS)

AIMS

To investigate the best glucose monitoring strategy for maintaining euglycaemia by comparing self-monitoring of blood glucose with continuous glucose monitoring, with or without an alarm function.

METHODS

A 100-day, randomized controlled study was conducted at four European centres, enrolling 160 patients with Type 1 or Type 2 diabetes, on multiple daily insulin injections or continuous subcutaneous insulin infusion. Participants were randomized to continuous glucose monitoring without alarms (n = 48), continuous glucose monitoring with alarms (n = 49) or self-monitoring of blood glucose (n = 48).

RESULTS

Time spent outside the glucose target during days 80-100 was 9.9 h/day for the continuous glucose monitoring without alarms group, 9.7 h/day for the continuous glucose monitoring with alarms group and 10.6 h/day for the self-monitoring of blood glucose group (P = 0.18 and 0.08 compared with continuous glucose monitoring without and with alarms, respectively).The continuous glucose monitoring with alarms group spent less time in hypoglycaemia compared with the self-monitoring of blood glucose group (1.0 h/day and 1.6 h/day, respectively; 95% CI -1.2 to -0.1; P = 0.030). Among those treated with continuous subcutaneous insulin infusion, time spent outside the glucose target was significantly different when comparing continuous glucose monitoring without alarms and self-monitoring of blood glucose (-1.9 h/day; 95% CI -3.8 to 0.0; P = 0.0461) and when comparing continuous glucose monitoring with alarms and self-monitoring of blood glucose (-2.4 h/day; 95% CI -4.1 to -0.5; P = 0.0134). There was no difference in HbA1c reduction from baseline in the three groups; however, the proportion of participants with a reduction of ≥ 6 mmol/mol (≥ 0.5%) was higher in the continuous glucose monitoring without alarms (27%) and continuous glucose monitoring with alarms groups (25%) than in the self-monitoring of blood glucose group (10.6%).

CONCLUSIONS

This study shows that the use of continuous glucose monitoring reduces time spent outside glucose targets compared with self-monitoring of blood glucose, especially among users of insulin pumps.

Real-time continuous glucose monitoring in type 1 diabetes: a qualitative framework analysis of patient narratives

OBJECTIVE

This study analyzed narratives about experiences of real-time continuous glucose monitoring (CGM) in people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

People with type 1 diabetes using CGM and caregivers completed an online survey. Questions included duration of CGM, frequency of sensor wear, funding, and a free narrative about experiences or views about CGM. We used qualitative framework analysis to analyze 100 responses; 50% of participants were aged ≥ 18 years.

RESULTS

Most participants (87%) used CGM with insulin pump therapy, 71% used sensors ≥ 75% of the time, and 66% received funding for CGM from the National Health Service. Four themes were identified: 1) metabolic control, 2) living with CGM (work and school, sleep, exercise, nutrition, frequency of self-monitoring of blood glucose [SMBG]), 3) psychological issues and patient/caregiver attitudes, and 4) barriers to CGM use (technical issues, financial issues, attitudes of healthcare professionals toward CGM). Despite some hassles, experiences were overwhelmingly positive, with improved glycemic control, diet and exercise management, quality of life, and physical and psychological well-being, as well as reduced frequency of SMBG. Technical problems included sensor inaccuracy and unreliability, and "alarm fatigue." The advantages of CGM used with an insulin pump with automatic suspension of insulin delivery during hypoglycemia were recorded by several participants, noting reduced hypoglycemia frequency and fear of nocturnal hypoglycemia.

CONCLUSIONS

Patient and caregiver narratives indicate that CGM is a valuable addition to diabetes care for many with type 1 diabetes.

The benefits, limitations, and cost-effectiveness of advanced technologies in the management of patients with diabetes mellitus

Hypoglycemia mitigation is critical for appropriately managing patients with diabetes. Advanced technologies are becoming more prevalent in diabetes management, but their benefits have been primarily judged on the basis of hemoglobin A1c. A critical appraisal of the effectiveness and limitations of advanced technologies in reducing both A1c and hypoglycemia rates has not been previously performed. The cost of hypoglycemia was estimated using literature rates of hypoglycemia events resulting in hospitalizations. A literature search was conducted on the effect on A1c and hypoglycemia of advanced technologies. The cost-effectiveness of continuous subcutaneous insulin infusion (CSII) and real-time continuous glucose monitors (RT-CGM) was reviewed. Severe hypoglycemia in insulin-using patients with diabetes costs $4.9-$12.7 billion. CSII reduces A1c in some but not all studies. CSII improves hypoglycemia in patients with high baseline rates. Bolus calculators improve A1c and improve the fear of hypoglycemia but not hypoglycemia rates. RT-CGM alone and when combined with CSII improve A1c with a neutral effect on hypoglycemia rates. Low-glucose threshold suspend systems reduce hypoglycemia with a neutral effect on A1c, and low-glucose predictive suspend systems reduce hypoglycemia with a small increase in plasma glucose levels. In short-term studies, artificial pancreas systems reduce both hypoglycemia rates and plasma glucose levels. CSII and RT-CGM are cost-effective technologies, but their wide adoption is limited by cost, psychosocial, and educational factors. Most currently available technologies improve A1c with a neutral or improved rate of hypoglycemia. Advanced technologies appear to be cost-effective in diabetes management, especially when including the underlying cost of hypoglycemia.

Clinical accuracy of a continuous glucose monitoring system with an advanced algorithm

We assessed the performance of a modified Dexcom G4 Platinum system with an advanced algorithm, in comparison with frequent venous samples measured on a laboratory reference (YSI) during a clinic session and in comparison to self-monitored blood glucose (SMBG) during home use. Fifty-one subjects with diabetes were enrolled in a prospective multicenter study. Subjects wore 1 sensor for 7-day use and participated in one 12-hour in-clinic session on day 1, 4, or 7 to collect YSI reference venous glucose every 15 minutes and capillary SMBG test every 30 minutes. Carbohydrate consumption and insulin dosing and timing were manipulated to obtain data in low and high glucose ranges. In comparison with the laboratory reference method (n = 2,263) the system provided a mean and median absolute relative differences (ARD) of 9.0% and 7.0%, respectively. The mean absolute difference for CGM was 6.4 mg/dL when the YSIs were within hypoglycemia ranges (≤ 70 mg/dL). The percentage in the clinically accurate Clarke error grid A zone was 92.4% and in the benign error B zone was 7.1%. Majority of the sensors (73%) had an aggregated MARD in reference to YSI ≤ 10%. The MARD of CGM-SMBG for home use was 11.3%. The study showed that the point and rate accuracy, clinical accuracy, reliability, and consistency over the duration of wear and across glycemic ranges were superior to current commercial real-time CGM systems. The performance of this CGM is reaching that of a self-monitoring blood glucose meter in real use environment.

Perceived accuracy in continuous glucose monitoring: understanding the impact on patients

In terms of accuracy and reliability, the technology of real-time (RT) continuous glucose monitoring (CGM) is advancing quickly. Still, current devices are imperfect; as a result, patient complaints and frustrations are not uncommon. How do patients' perceptions of device accuracy affect their experience with RT-CGM? In this article, we argue that patients' satisfaction, or dissatisfaction, with accuracy has a major impact on how much they are likely to trust the device and how confident they may feel in using the information that is displayed. The available data suggest that greater satisfaction with accuracy is linked to better RT-CGM adherence, more confident and aggressive insulin adjustments, improvements in quality of life, reduced reliance on self-monitoring of blood glucose, and--potentially--less alarm fatigue. As the technology continues to mature, RT-CGM will become increasingly accurate and patients' confidence and trust in the available devices will likely grow, leading to greater uptake and more proactive use of RT-CGM.

Accuracy and acceptability of the 6-day Enlite continuous subcutaneous glucose sensor

OBJECTIVE

This study evaluated the performance and acceptability of the Enlite(®) glucose sensor (Medtronic MiniMed, Inc., Northridge, CA).

SUBJECTS AND METHODS

Ninety adults with type 1 or type 2 diabetes wore two Enlite sensors on the abdomen and/or buttock for 6 days and calibrated them at different frequencies. On Days 1, 3, and 6, accuracy was evaluated by comparison of sensor glucose values with frequently sampled plasma glucose values collected over a 12-h period. Accuracy was assessed at different reference glucose concentrations and during times when absolute glucose concentration rates of change were <1, 1-2, and >2 mg/dL/min. The sensor's ability to detect hypoglycemia or hyperglycemia was evaluated with simulated alerts. Subject satisfaction was evaluated with a 7-point Likert-type questionnaire, with a score of 7 indicating strong agreement.

RESULTS

With abdomen sensors under actual-use calibration (mean, 2.8 ± 0.9 times/day), the overall mean (median) absolute relative difference (ARD) values between sensor and reference values were 13.6% (10.1%); the corresponding buttock sensor ARD values were 15.5% (10.5%). With abdomen sensors under minimal calibration (mean, 1.2 ± 0.9 times/day), the mean (median) ARD values were 14.7% (10.8%). Mean ARD values of abdomen sensors at rates of change of <1, 1-2, and >2 mg/dL/min were 13.6%, 12.9%, and 16.3%, respectively. With abdomen sensors, 79.5% and 94.1% of hypoglycemic and hyperglycemic events, respectively, were correctly detected; 81.9% and 94.9% of hypoglycemic and hyperglycemic alerts, respectively, were confirmed. The failure rates for abdomen and buttock sensors were 19.7% and 13.9%, respectively. Mean responses to survey questions for all subjects related to comfort and ease of use were favorable.

CONCLUSIONS

The Enlite sensor provided accurate data at different glucose concentrations and rates of change. Subjects found the sensor comfortable and easy to use.

A new-generation continuous glucose monitoring system: improved accuracy and reliability compared with a previous-generation system

BACKGROUND

Use of continuous glucose monitoring (CGM) systems can improve glycemic control, but widespread adoption of CGM utilization has been limited, in part because of real and perceived problems with accuracy and reliability. This study compared accuracy and performance metrics for a new-generation CGM system with those of a previous-generation device.

SUBJECTS AND METHODS

Subjects were enrolled in a 7-day, open-label, multicenter pivotal study. Sensor readings were compared with venous YSI measurements (blood glucose analyzer from YSI Inc., Yellow Springs, OH) every 15 min (±5 min) during in-clinic visits. The aggregate and individual sensor accuracy and reliability of a new CGM system, the Dexcom(®) (San Diego, CA) G4™ PLATINUM (DG4P), were compared with those of the previous CGM system, the Dexcom SEVEN(®) PLUS (DSP).

RESULTS

Both study design and subject characteristics were similar. The aggregate mean absolute relative difference (MARD) for DG4P was 13% compared with 16% for DSP (P<0.0001), and 82% of DG4P readings were within ± 20 mg/dL (for YSI ≤ 80 mg/dL) or 20% of YSI values (for YSI >80 mg/dL) compared with 76% for DSP (P<0.001). Ninety percent of the DG4P sensors had an individual MARD ≤ 20% compared with only 76% of DSP sensors (P=0.015). Half of DG4P sensors had a MARD less than 12.5% compared with 14% for the DSP sensors (P=0.028). The mean absolute difference for biochemical hypoglycemia (YSI <70 mg/dL) for DG4P was 11 mg/dL compared with 16 mg/dL for DSP (P<0.001).

CONCLUSIONS

The performance of DG4P was significantly improved compared with that of DSP, which may increase routine clinical use of CGM and improve patient outcomes.

Continuous glucose monitoring: current use and future directions

Continuous glucose monitoring (CGM) is an emerging technology that provides a continuous measure of interstitial glucose levels. In addition to providing a more complete pattern of glucose excursions, CGMs utilize real-time alarms for thresholds and predictions of hypo- and hyperglycemia, as well as rate of change alarms for rapid glycemic excursions. CGM users have been able to improve glycemic control without increasing their risk of hypoglycemia. Sensor accuracy, reliability, and wearability are important challenges to CGM success and are critical to the development of an artificial pancreas (or closed-loop system).

Evaluation of the performance of a novel system for continuous glucose monitoring

BACKGROUND

The performance of a continuous glucose monitoring (CGM) system in the early stage of development was assessed in an inpatient setting that simulates daily life conditions of people with diabetes. Performance was evaluated at low glycemic, euglycemic, and high glycemic ranges as well as during phases with rapid glucose excursions.

METHODS

Each of the 30 participants with type 1 diabetes (15 female, age 47 ± 12 years, hemoglobin A1c 7.7% ± 1.3%) wore two sensors of the prototype system in parallel for 7 days. Capillary blood samples were measured at least 16 times per day (at least 15 times per daytime and at least once per night). On two subsequent study days, glucose excursions were induced. For performance evaluation, the mean absolute relative difference (MARD) between CGM readings and paired capillary blood glucose readings and precision absolute relative difference (PARD), i.e., differences between paired CGM readings were calculated.

RESULTS

Overall aggregated MARD was 9.2% and overall aggregated PARD was 7.5%. During induced glucose excursions, MARD was 10.9% and PARD was 7.8%. Lowest MARD (8.5%) and lowest PARD (6.4%) were observed in the high glycemic range (euglycemic range, MARD 9.1% and PARD 7.4%; low glycemic range, MARD 12.3% and PARD 12.4%).

CONCLUSIONS

The performance of this prototype CGM system was, particularly in the hypoglycemic range and during phases with rapid glucose fluctuations, better than performance data reported for other commercially available systems. In addition, performance of this prototype sensor was noticeably constant over the whole study period. This prototype system is not yet approved, and performance of this CGM system needs to be further assessed in clinical studies.

Overview of a novel sensor for continuous glucose monitoring

The core element of a continuous glucose monitoring (CGM) system is the glucose sensor, which should enable reliable CGM readings in the interstitial fluid in subcutaneous tissue for a period of several days. The aim of this article is to describe the layout and constituents of a novel glucose sensor and the rationale behind the measures that were used to optimize its performance. In order to achieve a stable glucose sensor signal, special attention was paid to the sensor materials and architecture, i.e., biocompatible coating of the sensor, limitation of glucose flux into the working electrode, low oxidation potential by use of manganese dioxide, and a tissue-averaging sensor design. A series of in vitro and in vivo evaluations showed that the sensor enables stable and accurate glucose sensing in the subcutaneous tissue for up to 7 days. Parallel measurements with four sensors in a single patient showed a close agreement between these sensors. In summary, this high-performance needle-type glucose sensor is well suited for CGM in patients with diabetes.

The effect of real-time continuous glucose monitoring in pregnant women with diabetes: a randomized controlled trial

OBJECTIVE

To assess whether intermittent real-time continuous glucose monitoring (CGM) improves glycemic control and pregnancy outcome in unselected women with pregestational diabetes.

RESEARCH DESIGN AND METHODS

A total of 123 women with type 1 diabetes and 31 women with type 2 diabetes were randomized to use real-time CGM for 6 days at 8, 12, 21, 27, and 33 weeks in addition to routine care, including self-monitored plasma glucose seven times daily, or routine care only. To optimize glycemic control, real-time CGM readings were evaluated by a diabetes caregiver. HbA1c, self-monitored plasma glucose, severe hypoglycemia, and pregnancy outcomes were recorded, with large-for-gestational-age infants as the primary outcome.

RESULTS

Women assigned to real-time CGM (n = 79) had baseline HbA1c similar to that of women in the control arm (n = 75) (median 6.6 [range 5.3-10.0] vs. 6.8% [5.3-10.7]; P = 0.67) (49 [34-86] vs. 51 mmol/mol [34-93]). Forty-nine (64%) women used real-time CGM per protocol. At 33 weeks, HbA1c (6.1 [5.1-7.8] vs. 6.1% [4.8-8.2]; P = 0.39) (43 [32-62] vs. 43 mmol/mol [29-66]) and self-monitored plasma glucose (6.2 [4.7-7.9] vs. 6.2 mmol/L [4.9-7.9]; P = 0.64) were comparable regardless of real-time CGM use, and a similar fraction of women had experienced severe hypoglycemia (16 vs. 16%; P = 0.91). The prevalence of large-for-gestational-age infants (45 vs. 34%; P = 0.19) and other perinatal outcomes were comparable between the arms.

CONCLUSIONS

In this randomized trial, intermittent use of real-time CGM in pregnancy, in addition to self-monitored plasma glucose seven times daily, did not improve glycemic control or pregnancy outcome in women with pregestational diabetes.

Real-time continuous glucose monitoring or continuous subcutaneous insulin infusion, what goes first?: results of a pilot study

BACKGROUND

Dual devices allow both continuous subcutaneous insulin infusion (CSII) and real-time (RT) continuous glucose monitoring (CGM). Patients usually start with CSII, adding RT-CGM later (CGM post-CSII). Lack of use of RT-CGM is the main limiting factor of dual device results. Initiating RT-CGM before CSII (CGM pre-CSII) could increase RT-CGM frequency use and further improve glycemic control.

SUBJECTS AND METHODS

In this 26-week pilot study, we randomly assigned, via sealed envelopes, 16 CSII and RT-CGM to naive patients 14 years of age or older with type 1 diabetes mellitus (T1DM) to CGM post-CSII or CGM pre-CSII. The Paradigm® Veo™ (Medtronic Inc., Northridge, CA) was the dual device used in all patients. The primary end point was frequency of use of RT-CGM between both groups at week 26.

RESULTS

We detected a significant higher RT-CGM frequency use in the CGM pre-CSII group at week 26 (78.4±10.9% vs. 56.0±40.8%; P=0.01), although we did not detect hemoglobin A1c level differences. In addition, CGM pre-CSII patients presented less time in hypoglycemia (average daily area under curve <70 mg/dL per 24 h, 0.87±1.02 mg/dL/day vs. 3.32±2.19 mg/dL/day; P=0.021), and no severe hypoglycemia events were detected during 26 weeks in this group.

CONCLUSIONS

CGM pre-CSII is effective in increasing RT-CGM frequency use in T1DM patients. This is accompanied by a significant reduction in time in hypoglycemia.

What are the quality of life-related benefits and losses associated with real-time continuous glucose monitoring? A survey of current users

BACKGROUND

How does real-time (RT) continuous glucose monitoring (CGM) affect quality of life (QOL)? We explored the types and frequencies of diabetes-specific QOL changes resulting from RT-CGM as reported by current users and investigated what patient-reported factors predict these changes.

SUBJECTS AND METHODS

Current RT-CGM users (n = 877) completed an online questionnaire investigating perceived QOL benefits/losses since RT-CGM initiation and RT-CGM attitudes and behavior. Exploratory factor analysis (EFA) examined the 16 QOL benefit/loss items to identify underlying factors. Regression analyses examined associations between demographics and RT-CGM attitudes and behavior with the QOL factors emerging from the EFA.

RESULTS

Three major QOL factors emerged: Perceived Control over Diabetes, Hypoglycemic Safety, and Interpersonal Support. QOL improvement was common for Perceived Control over Diabetes and Hypoglycemic Safety (86% and 85% of respondents, respectively), although less common for Interpersonal Support (37%). Consistent independent predictors of perceived benefits were greater confidence in using RT-CGM data (P<0.001), satisfaction with device accuracy (P ≤ 0.05) and usability (P<0.01), older age (P<0.01), more frequent receiver screen views (P<0.05), and use of multiple daily injections (Hypoglycemic Safety and Interpersonal Support, P ≤ 0.05).

CONCLUSIONS

Diabetes-specific QOL benefits resulting from RT-CGM were common. Major predictors of QOL benefits were satisfaction with device accuracy and usability and trust in one's ability to use RT-CGM data, suggesting that "perceived efficacy," for both device and self, are key QOL determinants. Psychoeducational strategies to boost confidence in using RT-CGM data and provide reasonable device expectations might enhance QOL benefits.