Abstract
AIMS: We assessed adherence and long-term effects on HbA1c of unrestricted access to flash glucose monitoring (FGM) in a single diabetes centre. METHODS: In this observational study, we reviewed data files for all 411 patients with type 1 diabetes attending our clinic during a 2-year period. Adherence was reported in those who initiated FGM in our clinic (n = 321). Baseline and final HbA1c were noted for patients who continued FGM for more than 6 months without clinical conditions or interventions at baseline that could interfere with the effect of FGM on glycaemic control (n = 270). RESULTS: After 2 years, the fraction of patients using FGM increased from 3% to 72%. Adherence to FGM was 88%. Baseline and final HbA1c was median (interquartile range) 63 mmol/mol (56, 74) (7.9% (7.3, 8.9)) and 59 mmol/mol (53, 68) (7.6% (7.0, 8.4)), respectively. The estimated difference final-baseline HbA1c was -4 mmol/mol (95% CI -5, -3) (-0.4% (-0.5, -0.3)) (P < .001). No significant difference was seen for patients with baseline HbA1c ≤ 7% (53 mmol/mol). The interval from initiation of FGM to final HbA1c was median 562 days (IQR 417, 662). The number of scans/day was median 11 (IQR 8, 13) and correlated negatively with both final and baseline HbA1c but not with change in HbA1c. CONCLUSIONS: Following the introduction of unlimited access, nearly three quarters of the patients were FGM users. Long-term adherence was good, and HbA1c improved in all patients except in those with optimal glycaemic control at baseline.