A behavioural economics approach to personalised risk communication: nudging people with Type 2 diabetes towards better self-management

Type-2 diabetes mellitus (T2DM) is a major health burden, accounting for 12% of total healthcare expenditures worldwide. Recent forecasts estimate that 1 in 10 people will suffer from the condition by 2040. These figures are of great concern, particularly when T2DM has the potential to be well-controlled. By adhering to self-management behaviour, i.e. by making appropriate lifestyle changes, people with T2DM can delay and often prevent the onset of disease-related complications. However, in practice, many patients remain poorly controlled and the most effective method to motivate sustained adherence to self-management is unclear. Among recent motivation strategies, those informed by behavioural economics have raised growing interest in many different areas. The core principle of behavioural economics is to identify specific errors in the way people make decisions (i.e. specific deviations from standard economic rationality) and target these to steer people’s choices towards a given (recommended) direction. Following this approach, I aim to develop an innovative behavioural economic-informed intervention for people with T2DM with the objective of motivating sustained adherence to self-management in this population.
The first part of the Thesis was concerned with investigating the factors known to have an influence on patients’ decision to adhere to self-management. Firstly, I systematically reviewed all studies exploring the risk perceptions for diabetes-related complications in T2DM populations. I found that patients tend to largely underestimate their risks, especially those for cardiovascular complications, and express an optimistic bias (i.e. they tend to feel less at risk than their peers). Given the positive association between risk perceptions and adherence to self-management, these findings suggested the need for more effective risk communication addressed to this population. As a result, I further explored the decision-making processes of people with T2DM to identify relevant behavioural economic material. I measured the risk attitudes under prospect theory of 120 individuals, half of whom were diagnosed with T2DM. Focusing on a hypothetical trade-off between health outcomes and self-management, I found that patients express strong risk and loss aversion. This suggested that non-adherence to self-management may not be explained by a particular risk-seeking behaviour in this population. Consequently, this confirmed the need for better risk communication.
In the second part of the Thesis, I developed an innovative risk communication tool entitled PERCODIA. Informed by the behavioural economic findings of the first part, PERCODIA is aimed to better deliver personalised risk information to people with T2DM. I first reviewed the risk communication literature to identify the best ways of taking advantage of these behavioural economic findings. Both the content and the format of the tool were selected for this purpose. I then designed and conducted a pilot randomised control trial (RCT) to assess the feasibility of using PERCODIA in a primary care setting and evaluate its impact on risk recall and self-management behaviour. The trial comprised 40 participants with poorly controlled T2DM randomly allocated to usual care supported by PERCODIA or usual care only. The results showed that using PERCODIA in routine primary care is not only feasible, but also well-received by both doctors and patients. The intervention significantly improved recall of risk information after 12 weeks and motivated intentions to improve dietary behaviour. These promising results support the development of a larger RCT to assess the impact of PERCODIA on long-term self-management behaviour in poorly controlled T2DM populations. Given the significant challenges and opportunities in this patient population, robust evidence of a positive effect, even moderate, would greatly benefit both patients and the healthcare system.

Keywords: Self-Management
Nudge
Behavioural Economics
Type 2 Diabetes
Risk Communication
Advisor: Gray, A
Leal, J