Cardiovascular disease is the leading cause of morbidity and mortality in the United States. Physical activity has been demonstrated to improve health and reduce cardiovascular events. For example, exercise-based rehabilitation reduces death by up to 30% among patients with ischemic heart disease. However, only 30% of patients currently participate, and most patients do not obtain enough regular physical activity on their own.
Mobile health technologies such as wearable devices and smartphones are growing in adoption. These devices could be used in digital health interventions to passively monitor behavior in this high-risk patient population. Insights from behavioral economics – a field that leverages insights from psychology to address predictable barriers to behavior change – could be used to devise interventions that use these technologies to motivate greater physical activity.
We designed a home-based, remotely-monitored digital health intervention that used loss-framed financial incentives, personalized goal setting, and wearable devices to increase physical activity. We conducted a 24-week clinical trial, enrolling 105 patients with ischemic heart disease. Patients established a baseline step count and then were randomly assigned to a control arm with no interventions, or a financial incentive arm. Patients in the incentive arm received a daily step goal that increased gradually from their baseline to a target goal for a total of 16 weeks. Patients were then followed for an additional eight weeks without incentives.
The intervention led to significant increases in physical activity compared to the control, that were sustained in the follow-up period. Patients in the intervention had 1,368 more steps per day during the maintenance intervention period (P <0.01) and 1,154 more steps per day in the two months after the intervention completed (P <0.01). Over the six-month trial, the average patient in the intervention walked about 100 miles more than the average patient in the control.