Mixed Methods Study Exploring the Impact of Hybrid Closed-loop Systems on Patient Reported Outcomes in People With Type I Diabetes and Their Partners

Background:

Type 1 diabetes (T1D) is a complex lifelong autoimmune condition, characterized by the destruction of the β-cells of the pancreas. There is no cure. Management of type I diabetes mandates the use of exogenous insulin and frequent (>8 times per day) monitoring of blood glucose levels to get good glycaemic control. Over 42 factors affect blood glucose levels (www.diatribe.org). Factors that affect blood glucose levels include but are not limited to: exercise/activity, dietary intake, other medications, other diseases, environment, behaviour, and decisions. The correct dosing of insulin to achieve optimal blood glucose control is complex, requiring the person to take multiple predictable and often unpredictable factors into account.

Ongoing lifelong self-management is a relentless burden, with people often finding it difficult to cope [1] - there is "no holiday". T1D is associated with significantly lower quality of life and daily functioning and has been associated with increased rates of depression[2, 3], not just in people with diabetes but also in their partners [4]. These associations with diabetes specific distress, depression, anxiety and overall well-being are reported to be worse with higher HbA1c [5] (a measure of long-term glucose control that is associated with the risk of complications). Diabetes distress as the "significant negative psychological reactions related to emotional burdens and worries specific to an individual's experience in having to manage a severe complicated and demanding chronic disease such as diabetes." (ADA) [6] Multiple factors including constant need to make important timely decisions about insulin doses, blood glucose levels, food intake, predicted/unpredicted activity and the ongoing fear of developing long-term complications of diabetes [7]. Diabetes distress is prevalent (9-month incidence 54.4% among adults with type I diabetes) [8]. High diabetes distress scores coupled with the unrelenting nature of diabetes are associated with higher HbA1c, self-management and dietary/lifestyle choices [9].

Hypoglycaemia is the commonest acute complication of insulin therapy for type 1 diabetes and is widely acknowledged as a major barrier to achieving optimal glucose control. Fear of hypoglycaemia is also a major factor contributing to anxiety and diabetes distress, and that often is a barrier for people to achieve target glucose levels.

NICE currently recommends multiple daily injections as the therapy of choice initially for all adults with T1D. This requires them to measure their glucose 4-10 times a day and use self-management skills such as carbohydrate counting and appropriate adjustments for exercise, illness and stress etc to adjust amounts of insulin given by multiple injections through the day. The insulin usually consists of long-acting insulin taken once or twice daily (basal), and rapid acting insulin taken with each meal or to correct high glucose readings between meals (boluses). In recent years, a number of new technologies have emerged to support people with T1D to achieve better glucose control and also improve quality of life and reduce the burden of living with diabetes. Insulin pumps, also called continuous subcutaneous insulin infusion (CSII) are small pager sized devices that continuously infuse rapid acting insulin to provide the basal insulin, and the user can use buttons on the machine to take small and precise boluses to cover meals or corrections.