Effectiveness of continuous glucose monitoring in a clinical care environment: evidence from the Juvenile Diabetes Research Foundation continuous glucose monitoring (JDRF-CGM) trial

Abstract

Objective: To determine whether continuous glucose monitoring (CGM) is effective in the management of type 1 diabetes when implemented in a manner that more closely approximates clinical practice.

Research design and methods: After completion of a 6-month randomized controlled trial (RCT) evaluating CGM in children, adolescents, and adults with type 1 diabetes, CGM was initiated in the trial's control group with less intensive training and follow-up than was included in the RCT. Subjects had an outpatient training session, two follow-up phone calls, and outpatient visits at 1, 4, 13, and 26 weeks. For subjects with baseline A1C > or =7.0%, the primary outcome was change in A1C at 6 months.

Results: CGM use decreased from a median of 7.0 days/week in the first month in the > or =25-year-old group, 6.3 days/week in the 15-24 year olds, and 6.8 days/week in the 8-14 year olds to 6.5, 3.3, and 3.7 days/week in the 6th month, respectively (P < 0.001 for each age-group). Among subjects with baseline A1C > or =7.0%, CGM use was associated with A1C reduction after 6 months (P = 0.02 adjusted for age-group). Severe hypoglycemia decreased from 27.7 events per 100 person-years in the 6-month control phase of the RCT to 15.0 events per 100 person-years in the 6-month follow-up CGM phase (P = 0.08).

Conclusions: Frequent use of CGM in a clinical care setting may improve A1C and reduce episodes of hypoglycemia. However, sustained frequent use of CGM is less likely in children and adolescents than in adults.

Trial registration: ClinicalTrials.gov NCT00406133.

Figure 1

CGM use over 6 months according to age-group. Box plots indicating sensor use in each 4-week time period for the 212 subjects who completed the study (two subjects who did not complete the study are not included) are shown. The top and bottom of the boxes denote the 25th and 75th percentiles, the line represents the median, and the dot represents the mean. The numbers of subjects who did not use CGM during a 4-week period are indicated below each box plot (these data are included in each box plot).