Objective: To examine the relationship between risk factors for low patient activation and change in patient activation, well-being, and health outcomes in people with type 2 diabetes mellitus ... Show moreObjective: To examine the relationship between risk factors for low patient activation and change in patient activation, well-being, and health outcomes in people with type 2 diabetes mellitus (T2DM). Method: A longitudinal prospective study was conducted with measurements at baseline and 20-week follow-up among 603 people with T2DM participating in a group-based walking intervention. Patient activation and risk factors were assessed using online questionnaires. Health outcomes were assessed in participants' general practices. Results: No association was found between risk factors for activation and change in patient activation. Patient activation significantly increased (t(602) = 2.53, p = 0.012) and was associated with an increase in emotional well-being (beta = 0.22), exercise behavior (beta = 0.17), general diet behavior (beta = 0.20), and a reduction in BMI (beta = -0.28), weight (beta = -0.29), and HbA1c (beta = -0.27). Conclusion: Favorable changes in patient activation, self-management, well-being, and health outcomes occurred during a walking intervention, despite highly prevalent risk factors for low activation and less engagement in self-management. Practice implications: Group-based walking interventions might empower people with T2DM to begin taking a larger role in their self-care and improve (mental) health outcomes. Vulnerable groups of patients (with multiple risk factors for low activation) can change and presumably need this kind of interventions to be able to change. Show less