Development of a complex digital lifestyle intervention for individuals with prediabetes – Using the Medical research Council (MRC) framework

Background: Prediabetes raises the risk of developing type 2 diabetes (T2D) and related complications, making management vital to lessen diabetes-related burdens. Intensive lifestyle interventions can reduce the risk of T2D, but their high resource demands limit widespread use. In prediabetes, digital interventions are effective and may improve accessibility to preventive healthcare by reducing costs. However, findings vary, likely due to insufficient systematic development and reporting of complex interventions, which are crucial for effectiveness and replication. Many health interventions are considered complex, e.g., due to multiple interacting components. This study reports the development process of a complex digital lifestyle intervention for individuals with prediabetes. Methods: The Medical Research Council (MRC) framework guided the development process. This paper reports on the first phase of the MRC framework; the intervention development. The development was divided into four phases, integrating evidence from current literature and stakeholder engagement. A theoretical framework, combining the Theoretical Domains Framework (TDF) and the Behavior Change Technique (BCT) taxonomy, was applied to determine mechanisms of behavior change and intervention content. The structure and components of the interventions were developed to incorporate the identified mechanisms and content. Results: The developed intervention is structured around a starting period, a 12-week active intervention period, a closing period, and a follow-up period. The active intervention comprises four main components: 1) Individual contact, 2) Education, 3) Exercise, and 4) Social community, each with several subcomponents. The intervention integrates 29 unique BCTs targeting 12 unique mechanisms of behavior change identified from the TDF framework. Conclusion: This study developed a complex digital lifestyle intervention for individuals with prediabetes, integrating evidence, theory, and stakeholder engagement. While further development and testing are needed, the study provides a systematic description of the development process, addressing gaps in transparency and supporting effective outcomes, replication, and implementation in clinical practice. Abbreviations: BCT, Behavior Change Techniques; CReDECI, Criteria for Reporting the Development and Evaluation of Complex Interventions in Healthcare; MRC, Medical Research Council; PROs, Patient-related outcomes; TDF, Theoretical Domain Framework; T2D, type 2 diabetes.