Continuous Glucose Monitoring Adherence: Lessons From a Clinical Trial to Predict Outpatient Behavior

This study reports continuous glucose monitoring (CGM) adherence patterns and contributing factors in patients who were part of a 6-month clinical trial using sensor augmented pump therapy with low glucose insulin suspension.

CGM data from 38 patients using sensor augmented pump therapy for 6 months were analyzed. CGM adherence was defined by having a working sensor available and determined by the time it was switched on as a proportion of available time for the 6 month study period with allowance for practical CGM use. Age, gender, HbA1c, duration of diagnosis, capillary blood glucose testing frequency, sensor accuracy, and insulin pump alarm frequency were characterized and examined for an association with CGM adherence.

Overall CGM adherence was 75% (range: 35% to 96%), CGM adherence was demonstrated to fall after 9 to 11 weeks before reaching a steady rate. CGM adherence patterns showed substantial variation. Mean adherence differed (P < .01) between age groups 72% (<12 years), 69% (12-18 years), and 88% (≥18 years). Sensor accuracy predicted adherence, where every 1% decline in mean absolute difference in a given week was associated with a 0.5% decline in sensor adherence (P < .01). Gender, HbA1c, duration of diagnosis, capillary blood glucose testing frequency, and insulin pump alarm frequency were not associated with CGM adherence.

CGM adherence and patterns of use are individualized. However, a predictable fall in adherence at 9 to 11 weeks may present an opportunity for timed interventions to increase CGM use. Adolescent age and sensor accuracy predict CGM adherence.