Powerful together with diabetes, a group-based self-management intervention for patients with type 2 diabetes from lower educational groups: study protocol for a hybrid type 2 evaluation.

Introduction: Type 2 diabetes mellitus (T2DM) is a major burden on public health worldwide. To reduce adverse events and complications, effective T2DM self-management is required. Self-management and glycaemic control are generally poorer in lower educated people compared with higher educated people. This study aims to assess the (cost-)effectiveness and to conduct a process evaluation of a diabetes self-management programme, 'Powerful Together With Diabetes' (PTWD), which is specifically developed for patients from lower educational groups.

Methods And Analysis: The PTWD programme is focused on attaining basic knowledge and skills for effective diabetes self-management. In a previous study (the Diabetes in Social Context (DISC) study), lower-educated participants enjoyed the PTWD programme as well as improved their T2DM-related behaviours. The design of the study is an effectiveness-implementation hybrid type 2 trial. We will conduct mixed methods effectiveness, process and economic evaluations. To investigate the (cost-)effectiveness, a two-arm quasi-experimental trial will be conducted with a parallel mixed method process evaluation. The primary outcome of the study is change in haemoglobin A1c levels from baseline to 12 months. Secondary outcomes include use of primary and secondary care, medication use, blood biomarkers, T2DM self-management health behaviours, anthropometrics, and quality of life. Data will be collected with questionnaires, physical activity trackers and registration data from general practitioner registries. To see if the results are maintained, we will also measure the outcomes 24 months after baseline. Study participants are patients from lower educational groups living with T2DM between 35 and 70 years old. Participants will be recruited through general practices, and the intervention will be held in community centres. Our aim is to include 114 participants in the intervention group and 570 participants in the control group.

Ethics And Dissemination: This study has been approved by the Medical Ethics Committee of the Academic Medical Center in Amsterdam (#2021_222). Participants will sign an informed consent form prior to enrolment. Manuscripts with the results of the effectiveness, economic and process evaluations will be published in peer-reviewed journals.

Trial Registration Number: ISRCTN12982302 ISRCTN registry (registered on 29 March 2022).