Loop is a DIY app for automated insulin delivery using an iPhone and commercial continuous glucose monitor (CGM) and insulin pump. An ongoing observational study evaluates glycemic control, adverse event rates, and patient-reported outcomes (PROs) among adults with type 1 diabetes (T1D). This abstract presents PROs data for the first 3 months using Loop.

Participants were recruited through online postings and packaging of the Loop RileyLink. Device data were collected via the Tidepool Mobile App, including available CGM data at enrollment. PROs evaluated diabetes distress, technology attitudes and problem solving, hypoglycemia fears and confidence, and sleep quality with validated surveys.

There were 290 new users who started Loop within the past 7 days. Complete data were available for 254; 5 stopped using Loop and 31 did not complete PROs at 3 months. Demographic and clinical characteristics are in the Table. t tests and effect sizes showed statistically (p<0.05) and clinically significant (d=0.2-0.6) benefits of less distress and hypoglycemia fear, more confidence in catching hypoglycemia, and better sleep quality. Users were consistent in their report of average ease to start Loop and Loop performing very well day and night. Over 90% would recommend Loop (scores of 4 or 5).

This is the first study to systematically measure PROs in people using a DIY system, with new users voicing high satisfaction and across the board positive PRO scores.


K.K. Hood: Research Support; Self; Dexcom, Inc. Speaker’s Bureau; Self; LifeScan, Inc., MedIQ. J.J. Wong: None. S. Hanes: None. R. Bailey: None. P. Calhoun: Stock/Shareholder; Self; Dexcom, Inc. R. Beck: None. V.R. Barnes-Lomen: None. J.W. Lum: None. B. Arbiter: Employee; Self; Tidepool. Stock/Shareholder; Self; Abbott Laboratories, Dexcom, Inc., Tandem Diabetes Care. D. Naranjo: None.


The Leona M. and Harry B. Helmsley Charitable Trust

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