Use of automated insulin delivery (AID) in people with type 1 diabetes (T1D) has increased in recent years. We analyzed data from the T1D Exchange Registry - an online longitudinal study following adults and children with T1D - to describe characteristics of AID use and its association with self-reported HbA1c, occurrence of diabetic ketoacidosis (DKA) symptoms, and occurrence of severe hypoglycemia events (SHE) . Of 12,065 participants (69.5% female, 87.5% non-Hispanic White, mean age 37.9 yrs, mean T1D duration 19.9 yrs) , 26.4% reported using AID, 43.6% using insulin pump without AID, and 30.0% using multiple daily injections (MDI) . Private insurance was reported in 77.4% of AID users, 74.9% pump without AID, and 66.3% MDI. Among the 3,185 AID users, 50.6% used predictive low glucose suspend (PLGS) features, including Medtronic 640G and Tandem Basal-IQ; 49.4% used hybrid closed-loop (HCL) , including DIY looping, Medtronic Auto Mode, and Tandem Control-IQ. Average HbA1c was lower in AID users than those using MDI and pump without AID; Incidence of SHE was lower among HCL users compared with PLGS users and AID users compared with MDI users (Table 1) . These cross-sectional real-world data support findings of previous clinical studies showing significant improvements in HbA1c with AID use, with HCL use providing additional protection against SHE.
J.Liu: None. W.Wolf: None. K.Miller: Research Support; Dexcom, Inc., Tandem Diabetes Care, Inc. C.Kelly: None. K.S.M.Chapman: None. M.Peter: None. D.Finan: None. H.Nguyen: None. K.Laferriere: None. C.Leon: None.
