Schedule of study visits/phone contacts when the participant is randomised to day-and-night closed -loop combined with pump suspend feature (intervention group)
| Visit/contact | Description | Start relative to previous/next visit/activity | Duration, hours | |
| Visit 1 | Recruitment visit: consent, HbA1c, screening bloods and questionnaires, urine pregnancy test | - | 1–4 | |
| Training and run-in (4 weeks) | Visit 2 | Insulin pump training and the initiation of study pump, competency assessment | Within 1–3 weeks of visit 1 | 3–4 |
| Visit 3 | CGM training, initiation of CGM, weekly contact via phone/email, competency assessment | Within 3–7 days of visit 2 | 2–3 | |
| Visit 4* | Review pump and CGM data, optimisation of treatment, compliance assessment, randomisation | After 4 weeks of visit 3 | <1 | |
| Contact | Qualitative interview (with a subset of participants/family members) | After randomisation but before visit 5 | <1 | |
| CL + LGS intervention (3 months) | Visit 5 | CL initiation at clinic/home: urine pregnancy test, CL and suspend feature training, competency assessment, HbA1c | Within 1 week of visit 4 | 2–6 |
| Visit 6* | Review use of study devices | After 24–48 hours of visit 5 | <1 | |
| Visit 7† | Review use of study devices | After 1 week of visit 5 | <1 | |
| Visit 8* | Review pump and CGM data | After 1 week of Visit 7 | <1 | |
| Visit 9* | End of first month: review pump and CGM data | After 2 weeks of visit 8 | <1 | |
| Visit 10* | End of second month: review pump and CGM data | After 4 weeks of visit 9 | <1 | |
| Visit 11 | End of closed-loop treatment arm (3 months): HbA1c, complete questionnaires and follow-up qualitative interviews | After 4 weeks of visit 10 | 1–3 |
*Could be done via phone/e-mail in the UK. Follow-up by phone is mandatory in the USA only.
†Could be done via phone/e-mail in the UK. In-person visit mandatory in USA only.
CGM, continuous glucose monitoring; CL, closed loop; HbA1c, glycated haemoglobin; LGS, low glucose suspend.