Table 1

Primary and secondary objectives

Glucose control (24 hours, day (0600–2400), night (0000–0600))
  1. CGM data:

    1. % Time <2.8 mmol/L

    2. % Time <3.3 mmol/L

    3. % Time <3.9 mmol/L

    4. % Time 3.9–7.8 mmol/L

    5. % Time 3.9–10.0 mmol/L (primary outcome)

    6. % Time>10.0 mmol/L

    7. % Time>13.9 mmol/L

    8. % Time>16.7 mmol/L

    9. SD and coefficient of variation of CGM values

    10. Mean glucose

  2. Average fasting blood glucose (mmol/L, Defined as fasting capillary blood glucose level on waking (between 5am and 9am), at least 6 hours after an insulin bolus for carbohydrate).

  3. Average glycaemic control as measured by HbA1c.

Clinical measures
  1. Change in auxological parameters (height, weight, BMI z-score).

  2. Change in total daily dose, including basal and bolus proportion, carbohydrate ratios and insulin sensitivity.

Psychosocial (refer to table 3 for details)
  1. Fear of hypoglycaemia.

  2. Hypoglycaemia awareness.

  3. Anxiety.

  4. Impact and satisfaction.

  5. Quality of life.

  6. Diabetes specific quality of life.

  7. Diabetes distress.

Semistructured interview.
Human–technology interaction
  1. Assess participant technology interaction and explore adherence patterns and approaches that may improve it.

Health-economic
  1. Assess the health economic impact of the MiniMed 670G.

Biomarkers (refer to box 1 for details)
  1. Assess the impact of the MiniMed 670G Insulin Pump Hybrid Closed-Loop System on panel of biomarkers (see box 1).

Performance parameters
  1. Proportion of time hybrid closed loop is active.

  2. Unplanned exits from closed loop (n).

  3. Sensor performance—mean absolute relative difference (MARD), sensor failures (n).

  4. Insulin delivery line failures.

Safety
  1. Hospitalisations rate for diabetic ketoacidosis.

  2. Episodes of severe hypoglycaemia over (defined having altered mental status and cannot assist in their care, is semiconscious or unconscious or in coma±convulsions and may require parenteral therapy (glucagon or intravenous glucose).

Healthcare provider experiences
  1. Tracking expectations of HCL system through the study.

  • BMI, body mass index; CGM, continuous glucose monitoring; HbA1c, haemoglobin A1c; HCL, hybrid closed loop.