AimsTo determine the effect of the use of intermittently scanned continuous glucose monitoring (isCGM) on acute diabetes-related complications in adult type 1 diabetes patients.MethodsSix hundred and forty-two adult type 1 diabetes patients with isCGM were identified from electronic health records in Siun sote region in Eastern Finland. A retrospective real-world analysis was conducted combining hospital admission and prehospital emergency service data to compare incidences of hypoglycemia requiring emergency medical support (EMS) involvement or hospital admission and diabetic ketoacidosis (DKA) before and after the start of isCGM. Data were collected from January 2015 to April 2020. Primary outcome was the rate of hypoglycemia requiring EMS involvement or hospital admission and DKA events. HbA1c was recorded at the start of isCGM and was compared with the last known HbA1c during the use of isCGM. The isCGM used in the study did not contain alarm functions.ResultsAltogether 220 hypoglycemic events were identified during the study period. Incidence rate of hypoglycemic events decreased after the start of isCGM (72 events, incidence rate 50 events/1000 person-years) compared with the time before the start (148 events, incidence rate 76 events/1000 person-years) (p= 0.043). The incidence rate of DKA decreased after the start of isCGM compared with time before isCGM use (4 and 15 events/1000 person-years, respectively;p= 0.002). The change in mean HbA1c was − 0.28% (− 3.1 mmol/mol) between baseline and the last HbA1c measurement (p< 0.001).ConclusionsIn addition to lowering HbA1c in type 1 diabetes patients, isCGM is also effective in preventing acute diabetes-related complications such as hypoglycemia requiring EMS involvement or hospital admission and DKA.