The Role of Self-efficacy Program for Self-management of People With Type Diabetes Mellitus

The goal of this clinical trial is to learn if a self-efficacy program can improve diabetes self-management behaviors in adults with Type 2 Diabetes Mellitus attending primary health centers (Puskesmas) in Yogyakarta, Indonesia. The main questions it aims to answer are: * Does a self-efficacy program improve diabetes self-management behaviors (measured by the Summary of Diabetes Self-Care Activities/SDSCA)? * Does a self-efficacy program enhance diabetes self-efficacy (measured by the Diabetes Self-Efficacy Scale)? Researchers will compare participants receiving the self-efficacy program (intervention group) to a waiting-list control group to see if the program leads to greater improvements in self-management and self-efficacy. Participants will: * Attend four weekly group sessions (60-90 minutes each) covering diabetes knowledge, goal setting, self-monitoring, and peer support * Complete questionnaires on diabetes self-management and self-efficacy at baseline and after the intervention period * Selected participants in the intervention group will take part in semi-structured interviews about their experience with the program