Individual case managers or “coaches”
The DPP primarily used an individual model of treatment, rather than a group-based approach, as had been used in many behavioral weight loss studies (12,13). This decision was based on the extensive screening process and number of arms in the trial (which limited the number of participants randomized to lifestyle each month) and the desire to intervene before a participant had the possibility of developing diabetes or losing interest in the program. The individual approach to therapy also allowed tailoring of intervention activities to the ethnically diverse population and those with low literacy. Adherence and maintenance activities included both individual and group approaches, based on the approaches used in the TONE trial (15).