This is a staggered randomised controlled trial that aims to assess the impact of an automated insulin delivery (AID) system on glucose, gastrointestinal and patient-reported outcomes.

Following a run-in period of 2 weeks, participants will be randomised to control or hybrid automated insulin delivery (AID) using the 780G system and will remain in the intervention phase of the study for 12 weeks (4-week control, then 4-week AID or Control and finally 4-week AID). The total duration for each participant will be 14 weeks. There are 5 study visits (combination of face to face or/and remote) and two telephone visits in total.

Inclusion Criteria:

• Aged 18 years of age or older
• Type 1 diabetes confirmed on the basis of clinical features
• Type 1 diabetes for greater than 1 year
• On an intensified insulin regimen with multiple dose injection or insulin pump for > 3 months
• HbA1c >7.5% (58mmol/mol) (or %TIR 3.9-10mmol/L <52% for participants already using a continuous glucose sensor)
• Gastroparesis Cardinal Symptom Index (GCSI) ≥ 18 or evidence of delayed gastric emptying on nuclear medicine gastric emptying study

Exclusion Criteria:

• Enrolled in other clinical trials
• Estimated glomerular filtration rate of ≤30ml/min
• Pregnant or planning pregnancy
• Have active malignancy or under investigation for malignancy
• Severe visual impairment
• Reduced manual dexterity
• Use of any automated insulin delivery system
• Unable to participate due to other factors, as assessed by the Chief Investigator