Background

Many people with type 1 diabetes develop severe microvascular complications including kidney failure, foot ulceration and deteriorating vision, and experience premature death from cardiovascular disease (CVD). The human cost in loss of quantity and quality of life (QoL) is matched by the economic consequences. Around 2–3% of those with diabetes in the UK currently account for 10% of the NHS budget.¹ The annual UK cost for managing kidney disease amounts to around £150M in type 1 diabetes.²

Keeping blood glucose levels close to non-diabetic levels reduces microvascular complications. In the Diabetes Control and Complications Trial (DCCT),³ a reduction in glycated haemoglobin (HbA_1c, a measure of glucose control) of 2 percentage points halved the risk of diabetic complications. However, this evidence did not initially lead to improved clinical practice in the UK.

The main reason that tight metabolic control is difficult to achieve is that current methods of insulin delivery cannot reproduce physiological insulin release by the pancreas. Furthermore, the relentless behavioural and technical demands of having to calculate appropriate doses of insulin and adjust for different situations (e.g. stress, exercise, carbohydrate consumption) in a way that attempts to reproduce normal physiology (in which correct doses are released automatically) are very challenging. Using injected insulin to control glucose levels aggressively is also potentially hazardous, with an increased risk of hypoglycaemia,^4,5 although in the long term the rewards are a reduced chance of microvascular complications and a prolonged life expectancy.

Despite these limitations, insulin therapy can control blood glucose effectively if patients can integrate different principles, including (1) understanding the effects of insulin, (2) appreciating which foods raise blood glucose and by how much, (3) recognising and treating hypoglycaemia and (4) anticipating exercise. Diabetes health-care professionals understand these principles and the crucial test is whether or not they can teach them to patients. In the 1980s the Diabetes Centre in Düsseldorf developed a 5-day structured training programme in intensive self-management using these principles, which demonstrated markedly improved glucose control yet reduced hypoglycaemia.⁶

In 2002, a multidisciplinary team, based in three centres and part of the group undertaking the work of this report, completed the Dose Adjustment For Normal Eating (DAFNE) trial,⁷ a randomised controlled trial (RCT) of the German intervention adapted for the UK. There were major improvements in QoL, sustained for up to 12 months (despite increased injections and blood tests), and falls in HbA_1c of 1.0% at 6 months and 0.7% at 12 months.

Principles of the complex educational intervention

One of the main principles underlying DAFNE flexible intensive insulin therapy (FIIT) is the separation of basal- and meal-related insulin. The basal or background insulin is a medium-acting insulin [neutral protamine Hagedorn (NPH), detemir or glargine), usually given as two doses, one just before bed and the other before breakfast. The doses are kept relatively constant to maintain the blood glucose within a given target range. The approach is designed so that the basal insulin doses should be able to keep the blood glucose reasonably controlled in the ‘fasting state’. Participants are taught to adjust the basal dose every few weeks. The evening dose, given the night before, is altered based on the fasting blood glucose measured before breakfast on the following morning. The morning dose is altered according to the pre-evening meal blood glucose.

An important skill taught in the DAFNE programme concerns the calculation of the fast-acting insulin dose, given before meals. The dose required is determined by estimating the carbohydrate content of the food about to be eaten in terms of the number of 10-g carbohydrate portions (CPs) and multiplying this by an individualised ratio of the number of insulin units to each CP (often 1 : 1). A correction to the insulin dose may also be required if the relevant pre-meal blood glucose level is above the target range. Additional adjustment may also be made if the participant anticipates other activities such as exercise. DAFNE diaries are provided so that blood glucose levels can be written down, along with the carbohydrate content of the meals eaten and the insulin doses used. These records are designed specifically to aid reflection and refine future insulin dose adjustment.

Courses

Individual courses are led by two trained educators (usually one diabetes nurse specialist and one dietitian) in a group setting with six to eight adults with type 1 diabetes. The courses are run over 5 days with the participants attending between 09.00 and 17.00 Monday to Friday. Courses are held in a large room. Some centres have a designated education room whereas other centres hold courses in community centres. Centres organising DAFNE courses are free to choose which of their patients attend, although those with serious complications, those with very poor blood glucose control (and who are probably missing insulin for psychological reasons) and those who have a poor command of English are generally excluded. The age of participants varies between 18 and 80 years and the duration of diabetes of those participating can range from newly diagnosed to > 50 years. The curriculum has been built on adult education principles, emerging from the concept of therapeutic education (a principle advanced by Assal et al.⁸ in the early 1980s), and adheres to the precept of social learning theory.⁹ It encourages inclusivity and participation and involvement by all.

Group feedback sessions on insulin adjustment and achieving target blood glucose levels take place at the beginning and end of each day. During the course, there are additional sessions on the simple pathophysiology of diabetes, insulin types and their duration of action, blood glucose monitoring, managing hypoglycaemia, diabetes complications, the purpose of the annual review and managing diabetes in special situations, for example illness, alcohol and exercise.

A group follow-up session is offered to participants at 6–12 weeks after each course (often poorly attended) but follow-up thereafter is not specified and is left to individual centres.

Quality control

The DAFNE educators are required to teach on at least one course every 6 months to maintain their skills and are intermittently peer reviewed by educators from other centres who have had additional training. DAFNE centres are audited on a 3-year cycle on the process of delivering the DAFNE programme and on local outcomes, particularly recorded changes in HbA_1c levels.

Rationale for the research programme

Despite the success of the DAFNE project, important questions remain unanswered. Many patients cannot sustain the approach and, in others, HbA_1c is unchanged or worsens after the course. These patients need additional input besides skills training to undertake effective self-management, perhaps a different course or undertaking it after specific pre-course preparation. A review of the original DAFNE cohort showed that, after 4 years, the HbA_1c level was only 0.2% below the baseline level, although psychosocial benefit was maintained.¹² These data and others showing that around half of DAFNE graduates remain poorly controlled emphasised that developing the DAFNE intervention was just a start and that more research was needed to both improve the effectiveness of the intervention and to support patients to manage their diabetes more effectively.

To improve the DAFNE programme, and indeed diabetes education in general, patients’ experiences needed to be better understood. We were unsure of the ‘active ingredients’ that foster (or hinder) improved self-care and/or QoL in complex educational interventions. We did not know which factors are critical (or incidental) to success. Delivering diabetes education to groups may be more effective than delivering diabetes education to individuals,¹³ but the reasons for this remain unclear. Given our limited understanding of how diabetes group education ‘works’, we may not have been using the most appropriate measures for its evaluation. To explore the DAFNE ‘black box’ we needed to record patient characteristics and psychosocial variables alongside an in-depth exploration of the problems and challenges encountered in sustaining intensive self-management over time.

In addition, the provision of a well-defined, quality-assured, educational and consistent programme delivered in centres across the UK allowed us to test the added benefit of new technologies in patients skilled in self-management. Thus, one of our workstreams involved the development of a model allowing us to measure the true benefit of continuous subcutaneous insulin infusion (CSII) in a RCT. Demonstrating the success of such an approach would allow us to establish the benefit of other emerging new treatments such as different forms of insulin delivery and techniques such as continuous glucose monitoring (CGM) in the future.

We recognise that type 2 diabetes is more common than type 1 diabetes and that the incidence of type 2 diabetes is increasing at a faster rate. However, when we initiated this work, the DAFNE collaborative was the only self-management programme for long-term conditions that has published evidence of effectiveness in a RCT and successfully rolled out care across the UK accompanied by a robust quality assurance programme with structured educator training and independent peer review. The work we proposed included a detailed exploration of factors determining success in a complex health educational intervention. Thus, we expected that the information gained from this approach would apply to both type 2 diabetes and other long-term conditions.

Objectives

The aim of this research programme was to use the DAFNE collaborative as a research test-bed to improve complex educational interventions in the management of type 1 diabetes and other long-term conditions.

Our objectives were to:

1. Develop a database to record outcomes and progress in adults with type 1 diabetes undertaking structured education.
2. Undertake psychosocial studies to determine factors explaining why individuals do well or badly after structured education using linked qualitative and quantitative approaches. We aimed to:

   1. identify which aspects of the complex intervention do and do not promote improved biomedical and psychosocial outcomes
   2. establish why some patients benefit more from DAFNE training than others
   3. identify factors that explain why improved glycaemic control following DAFNE training tends to decline over time.
3. Undertake two RCTs (one pilot) to improve self-management and develop an additional intervention to address glycaemic outcomes.
4. Utilise user involvement to develop more effective interventions.
5. Measure the cost-effectiveness of interventions over the short and long term.

Reports from the workstreams designed to address these objectives are presented in Chapters 2–8. Linkages between workstreams are indicated in the text.