The Loop Observational Study (LOS)

An Observational Study of Individuals With Type 1 Diabetes Using the Loop System for Automated Insulin Delivery

An observational study to collect data on the efficacy, safety, usability, and quality of life/psychosocial effects of the Loop DIY automated insulin delivery system.

Study Overview

• Status: Completed
• Conditions: Diabetes Mellitus, Type 1
• Intervention / Treatment: Device: Loop

Detailed Description

The study will include both adults and youth in the United States, with a recruitment goal of at least 300-1,250 participants. Data to be collected to address the study objective will include CGM metrics; HbA1c; insulin delivery data; carbohydrate data; activity data from HealthKit; self-reported adverse events (e.g., severe hypoglycemia, diabetic ketoacidosis, hospitalizations); self-reported device issues; and psychosocial and user experience/treatment satisfaction surveys.

Online forms will allow participants to report weekly device issues and serious adverse events including severe hypoglycemia, diabetic ketoacidosis, and hospitalizations. General data updates will be obtained after three, six, and 12 months (and every six months thereafter if study participation continues). A fingerstick blood sample will be collected for HbA1c measurement after three months for cohort A and after six and 12 months for both cohorts. Quality-of-life/psychosocial and treatment satisfaction questionnaires will be completed after six and 12 months; new users also will complete questionnaires after 3 months. Virtual focus groups will be completed within the first three months of starting Loop and at 12 months.

• Study Type: Observational
• Enrollment (Actual): 1212

Contacts and Locations

Study Locations

• United States
  • Florida
    • Tampa, Florida, United States, 33647
      • Jaeb Center for Health Research

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Individuals using or planning to use the Loop system

Description

Inclusion Criteria:

• Type 1 diabetes
• Currently have, or have ordered, the hardware devices necessary to use Loop
• Currently use Loop or have plans to start using Loop for insulin delivery
• Willing and able to provide informed consent (or be a parent or other legally authorized representative) and to provide the data and complete questionnaires that are part of the protocol
• Resident of U.S.

Exclusion Criteria:

• None

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Cohort A; Individuals who have not started Loop or who have been on Loop fewer than 7 days at the time of enrollment.	Device: Loop; The Loop System consists of an insulin pump (certain versions of Medtronic insulin pumps) and a Dexcom or Medtronic CGM. The system includes an iPhone with the Loop app and a RileyLink to communicate between the pump and iPhone. An Apple Watch may optionally be used with the system.
Cohort B; Participants who have been using Loop 7 or more days at the time of enrollment.	Device: Loop; The Loop System consists of an insulin pump (certain versions of Medtronic insulin pumps) and a Dexcom or Medtronic CGM. The system includes an iPhone with the Loop app and a RileyLink to communicate between the pump and iPhone. An Apple Watch may optionally be used with the system.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measure of Loop Safety by Self-Report of Diabetic Ketoacidosis (DKA) Events	Number of DKA events and event outcomes on the Adverse Event and Device Issue - Loop survey. DKA events are defined as the development of ketones with a diagnosis of DKA by a medical provider.	6 Months
Measure of Loop Safety by Self-Report of Severe Hypoglycemic Events	Number of severe hypoglycemic events and event outcomes on the Adverse Event and Device Issue - Loop survey. Severe hypoglycemia is defined as low blood sugar that affected the individual's ability to think such that they were unable to treat themselves and needed assistance from someone else. The individual may or may not have lost consciousness.	6 Months
Measure of Loop Safety by Self-Report of Hospitalization Events	Number of hospitalizations and event outcomes on the Adverse Event and Device Issue - Loop survey.	6 Months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measure of Loop Safety by Self-Report of Diabetic Ketoacidosis (DKA) Events	Number of DKA events and event outcomes on the Adverse Event and Device Issue - Loop survey. DKA events are defined as the development of ketones with a diagnosis of DKA by a medical provider.	12 Months
Measure of Loop Safety by Self-Report of Severe Hypoglycemic Events	Number of severe hypoglycemic events and event outcomes on the Adverse Event and Device Issue - Loop survey. Severe hypoglycemia is defined as low blood sugar that affected the individual's ability to think such that they were unable to treat themselves and needed assistance from someone else. The individual may or may not have lost consciousness.	12 Months
Measure of Loop Safety by Self-Report of Hospitalization Events	Number of hospitalizations and event outcomes on the Adverse Event and Device Issue - Loop survey.	12 Months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Loop Baseline General Data Collection	Self-report participant's basic information. No scale provided, variable responses.	Enrollment
Summary statistics for CGM metrics	Continuous CGM data from participant's Tidepool account.	6 months and 12 months
Loop Additional Form for Current Loop Users	Self-report of participant's use of Loop and Loop related features. No scale provided, variable responses.	Enrollment (cohort B), 3 Months (cohort A), 6 Months, and 12 Months
LoopHoles Survey	Self-report of participant's patterns of Loop use. No scale provided, variable responses.	Enrollment (cohort B), 3 Months (cohort A), 6 Months, and 12 Months
Pittsburgh Sleep Quality Index	Standardized questionnaire and scoring. Usual sleeping habits for past month. Questions 1 - 9. Overall scores range from 0 to 21, with lower values representing better sleep quality.	Enrollment, 3 Months (cohort A), 6 Months, and 12 Months
Satisfaction of diabetes technology.	Standardized Diabetes Technology Attitudes - 5 with likert scale questions. Each question is scored on a scale of 1 to 5, with a higher score indicating greater satisfaction with diabetes technology.	Enrollment, 3 Months (cohort A), 6 Months, and 12 Months
Automated Insulin Delivery Satisfaction	Change in satisfaction of using Loop. Measured using the standardized INSPIRE (Adult, Parent, and Child) questionnaires. The higher the score the more positive the opinion that automated insulin delivery has had a positive impact on the participant's life.	Enrollment (Cohort B), Month 3 (Cohort A), Month 6, Month 12
HbA1c	Blood sample.	Enrollment, Month 3 (Cohort A), Month 6, Month 12
Device issues related to Loop	Weekly self-report of any device issues that interfered with their ability to use Loop on the Adverse Event and Device Issue - Loop survey. No scale provided.	Weekly from 7 days after enrollment to 12 months
Hypoglycemia Confidence Scale	Standardized questionnaire. Confidence of managing hypoglycemia during daily tasks. Overall scores range from 1 to 4, with higher scores indicating greater confidence in managing hypoglycemia.	Enrollment, Month 3 (Cohort A), Month 6, Month 12
Hypoglycemia Fear Survey - Worry Scale	Standardized survey. Measures level of worry of low blood sugar, for Adult, Parent, and Child. Items are rated on a 5 point Likert scale from 0 to 4. Total scores and sub-scale scores are sum scores of all relative items. For the adult survey, the score ranges from 0-52. For the children's survey, the score ranges from 0-60. For the parent survey, the score ranges from 0-60. A higher score indicates greater fear of hypoglycemia.	Enrollment, Month 3 (Cohort A), Month 6, Month 12
Risk Taking Questions	Standardized questionnaire about risk taking behavior. Items are scored on a scale of 1 to 10, with a higher score indicating a greater disposition to take risks.	Enrollment, Month 3 (Cohort A), Month 6, Month 12
T1-DDS (Management Distress Items)	Standardized questionnaire. Feelings about diabetes management. Overall scores range from 1 to 6, with higher scores indicating higher distress over diabetes management.	Enrollment, Month 3 (Cohort A), Month 6, Month 12
Device Discontinuation or Non-start Reasons	No scale questionnaire allowing varied responses about why participant's stopped using Loop or why they never started.	Up to 12 months, as needed
Loop Follow-Up General Data Collection	Self-report of participant's basic information. No scale provided, variable responses.	Month 3 (Cohort A), Month 6, Month 12

Collaborators and Investigators

• Sponsor: Jaeb Center for Health Research
• Collaborators: Stanford University; Tidepool Project; RileyLink
• Investigators: Principal Investigator: John Lum, MS, Jaeb Center for Health Research

Publications and helpful links

General Publications

• Suttiratana SC, Wong JJ, Lanning MS, Dunlap A, Hanes SJ, Hood KK, Lal RA, Naranjo D. Qualitative Study of User Experiences with Loop, an Open-Source Automated Insulin Delivery System. Diabetes Technol Ther. 2022 Jun;24(6):416-423. doi: 10.1089/dia.2021.0485. Epub 2022 May 12.
• Wong JJ, Suttiratana SC, Lal RA, Lum JW, Lanning MS, Dunlap A, Arbiter B, Hanes SJ, Bailey RJ, Hood KK, Naranjo D. Discontinued Use of the Loop Insulin Dosing System: A Mixed-Methods Investigation. Diabetes Technol Ther. 2022 Apr;24(4):241-248. doi: 10.1089/dia.2021.0362.

Study record dates

Study Major Dates

• Study Start (Actual): January 17, 2019
• Primary Completion (Actual): March 31, 2020
• Study Completion (Actual): April 25, 2020

Study Registration Dates

• First Submitted: November 21, 2018
• First Submitted That Met QC Criteria: February 11, 2019
• First Posted (Actual): February 12, 2019

Study Record Updates

• Last Update Posted (Actual): August 14, 2020
• Last Update Submitted That Met QC Criteria: August 12, 2020
• Last Verified: August 1, 2020

More Information

Terms related to this study

• Keywords: Type 1 Diabetes; Loop; RileyLink
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Immune System Diseases; Autoimmune Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 1
• Other Study ID Numbers: LOOP

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No