Real-world Effect of Switching From Intermittently-scanned to Real-time Continuous Glucose Monitoring (Switch CGM Retro)

Inclusion Criteria: * 18 years or older as of the index date * Clinical diagnosis of T1D or T2D ≥ one year * Using either MDI or CSII therapy * Initiated a FreeStyle Libre® isCGM device between January 1, 2018 and July 31, 2023 (isCGM cohort) * Switched from a FreeStyle Libre® 1 or Libre 2® isCGM device to a Dexcom® G5 or G6 CGM device between April 1, 2018 and July 31, 2023 (rtCGM cohort) * Baseline HbA1c ≥7.0% for primary objective with rtCGM cohort * Baseline HbA1c ≥8.0% for key secondary objective comparing rtCGM cohort to isCGM cohort * Known rtCGM/isCGM start date (month and year) * Exclusive use of isCGM for ≥ 3 months * ≥ one HbA1c value up to 6 months (± 6 weeks) prior to index date (HbA1c value must be after isCGM initiation and no more than 6 weeks after the index date) * ≥ one HbA1c value 6-12 months (± 6 weeks) following the index date * Informed consent for their medical record data to be used for research purposes Exclusion Criteria: * Have a prior history of rtCGM within 12 months of the index date * Are pregnant at the time of isCGM initiation or time of switch to rtCGM * Used the isCGM or rtCGM for \< 3 months