Gamification-Augmented Home-Based Exercise for Peripheral Artery Disease (GAMEPAD)

A randomized trial of a gamification-enhanced home-based walking program compared with a standard home-based walking program in patients with intermittent claudication. Patients will be provided with a Fitbit device and set an exercise goal. Over the next 16 weeks, patients will receive text message reminders to exercise and daily steps will be tracked. Half of patients will be randomized to a gamified interface that leverages behavioral economic principles to encourage exercise.

Peripheral artery disease, atherosclerotic vascular disease involving the lower extremities, leads to functional limitation by causing leg pain with ambulation (intermittent claudication). Supervised exercise programs improve walking endurance in patients with intermittent claudication, but many patients are unable to travel to centers for treatment. In a recent trial, a home-based exercise program using wearable fitness trackers and telephone coaching failed to increase walking distance in patients with intermittent claudication, but this intervention did not leverage gamification or health behavior theory. Therefore, a randomized controlled trial was proposed comparing a gamification-enhanced home-based walking program with an attention control in patients with intermittent claudication. Patients in both arms will be provided with a wearable fitness tracker, wear the tracker for 2 weeks to establish a baseline daily step count and set a goal for step increase by the end of the 16-week study period. Patients in the attention control arm will receive daily text messages with a report of their previous day's step count. Patients in the gamification intervention arm will receive automated coaching via daily text messages and the intervention will also involve a precommittment pledge, slow ramp-up of step goals, weekly progression (or regression) through levels with loss-framing of points, and support from a family member or friend. After 16 weeks, change in daily step counts from baseline will be compared between study arms. Secondary behavioral phenotyping analyses will be undertaken to identify psychometric features associated with response to the gamification intervention.

Via the Way to Health platform, all patients will receive daily text messages that inform them of their previous day's step count for 24 weeks.

Participants have a 4-week ramp-up towards their step goal and are asked to maintain the goal for the rest of the study. They receive daily texts informing them if they met their step goal and biweekly texts to encourage walking for exercise. Participants are entered into a game. Each week they receive 70 points. If the step goal was met they keep their points. If not, they lose 10 points. At the end of the week if they have at least 40 points they move up a level. If not, they drop a level. Participants start in the middle of 5 levels. Participants choose a support partner who gets a weekly email with the participant's progress. We hold a 3-way phone call with the participant and partner to discuss ways they can help the participant meet their goal. Every 8 weeks, we have a follow up call if the participant is stuck in a lower level and restart them back at the middle level. In the follow-up period, participants continue to get a daily text stating if they met their step goal.

Participants in the intervention arm will receive gamification and social incentives as part of the intervention. See arm descriptions for more detail.

Change in daily number of minutes engaged in light, moderate, or vigorous physical activity from baseline to the intervention period, and from baseline to the follow-up period

Change in Walking Impairment Questionnaire score from baseline to the end of the intervention period, and from baseline to the end of the follow-up period. Participants are asked to rate the degree of difficulty of various physical activities, ranging from 0 (unable) to 4 (no difficulty). Scores are divided by the maximum number of points and presented on a scale of 0%-100% where 0% indicates they are unable to do the activity and 100% indicates they have no difficulty.

Change in PROMIS mobility, pain interference, and satisfaction with social roles and activities scores

Change in PROMIS (Patient-Reported Outcomes Measurement Information System) mobility, pain interference, and satisfaction with social roles and activities scores from baseline to the end of the intervention period, and from baseline to the end of the follow-up period. In the mobility survey, participants are asked to rate the level of difficulty of various physical activities on a scale from 1 to 5, where 1 means they are unable to do the activity and 5 means they have no difficulty. In the pain interference survey, they are asked to rate the degree to which pain interfered with various activities on a scale from 1 to 5, where 1 indicates pain did not interfere and 5 indicates pain very much interfered. For the satisfaction with social roles, participants are asked to rate how satisfied they are with their ability to perform various activities on a scale of 1-5, where 1 indicates they are not satisfied and 5 indicates they are very satisfied.

Change in SF-36 (36-Item Short Form Survey) physical functioning scale from baseline to the end of the intervention period, and from baseline to the end of the follow-up period. Participants are asked to self-report their health using 8 variously scaled scores. The scales are re-coded to values from 0 to 100, with 0 indicating lowest functioning/well-being and 100 indicating the highest.

Inclusion Criteria: At least 18 years of age Peripheral artery disease, defined as ankle-brachial index < 0.90, lower extremity CT scan or ultrasound consistent with PAD, angiography with ≥ 70% stenosis in any lower extremity artery, or a history of medical or surgical revascularization Owns a smartphone or tablet operating the iOS or Android operating system Exclusion Criteria: Unable or unwilling to provide informed consent, including but not limited to cognitive or language barriers (reading or comprehension) Critical limb ischemia, defined as rest pain, ulceration, or tissue loss involving the lower extremity Planned lower extremity revascularization Prior above or below the knee amputation Require a wheelchair or the use of a walking aid other than a cane Currently participating in a supervised exercise program for patients with PAD Anticipated life expectancy less than 6 months Any other reason why it is not feasible to complete the entire 6-month study Step count > 7500/day during the baseline data collection period