Gamification-Augmented Home-Based Exercise for Peripheral Artery Disease

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.

Eligibility Criteria:
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