Effectiveness of a Personalized Smartphone-assisted Coaching System to Improve Glucose Homeostasis in Adults With Prediabetes: Rationale and Study Protocol - Pilot Study

The mobile phone app Sweetch seeks to increase leisure time physical activity rather than formal exercise through the use of a behavioral analytics engine that continuously process various aspects of the user's life habits, taking into account the user's demographics, behavioral change status, schedule, actual activity patterns, and more. The rationale behind this approach is that long-term adherence and patient engagement are more likely to be achieved when demands on manual user data entry are kept at a minimum. Compared to similar smartphone-assisted prevention apps, there are two novel features of the Sweetch app that may increase its efficacy. First, it uses a "just-in-time" adaptive intervention" approach that tailors recommendations to the user's day-to-day routine and his or her readiness for behavioral change. Second, and most importantly, it requires no direct involvement by the user, since all the necessary data is collected using built-in tracking pedometers, accelerometer and GPS (Global Positioning System) sensors on smartphones. In contrast, interventions that focus on dietary changes (i.e. calorie reduction, change in macronutrient content), require active user tracking at every meal, which is difficult to maintain in the long-term even with the use of sophisticated, electronic calorie counting tools. For these reasons, the Sweetch app may achieve greater long-term adherence, which is usually a limiting factor to efficacy of mobile health interventions.