Effectiveness of Continuous Glucose Monitoring in a Clinical Care Environment: Evidence from the JDRF-CGM Trial

  1. Roy W. Beck, M.D., PhD (jdrfapp{at} and
  2. Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group


    Objective: To determine whether continuous glucose monitoring (CGM) is effective in the management of type 1 diabetes (T1D) when implemented in a manner that more closely approximates clinical practice.

    Research Design and Methods: After completion of a 6-month randomized clinical trial (RCT) evaluating CGM in children, adolescents, and adults with T1D, 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 ≥7.0%, the primary outcome was change in A1c at 6 months.

    Results: CGM use decreased from median of 7.0 days/week in the first month in the ≥ 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 sixth month, respectively (P<0.001 for each age group). Among subjects with baseline A1c ≥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.


      • Received August 12, 2009.
      • Accepted October 5, 2009.

    This Article

    1. Diabetes Care
    1. Online-Only Appendix
    2. All Versions of this Article:
      1. dc09-1502v1
      2. 33/1/17 most recent