Improving Walking Performance in Patients With Peripheral Artery Disease Through Wearable Activity Trackers

Supervised exercise therapy (SET) is a structured program of exercise designed for individuals with peripheral artery disease (PAD) and intermittent claudication (IC). It consists of 12 weeks of intermittent treadmill walking to moderate to severe claudication pain at a speed of ≈2 mph and at a grade equal to 40% of the highest workload achieved during the baseline maximal treadmill test, with intermittent period of rest, for at least 3 times per week with a minimum of 30-45 minutes per session

The WAM use in this study is the FitBit Inspire 3 Advanced Activity Tracker (FitBit Inc. San Francisco, CA, USA), which is a commercially available tri-axis accelerometer and heart rate monitor capable of continuous monitoring of heart rate using LED sensor, and activities including daily steps count and derived daily activity level, detection of arrythmia and measuring peripheral capillary oxygen saturation. Fitbit devices connect with HOBBIT-PAD platform which was developed specifically for patients with PAD based on user-centred design. It contains patient education information, instruction for exercise, activity record, and embedded messaging function between the patient and the research team about any technical and clinical issue. Important and thorough customizations will be made to tailor this mobile health platform for this study, which includes the addition of patient education materials on PAD and its management, tips on health eating and lifestyle, and tips on exercise.

Instructions for HBET are programmed according to the AHA recommendation on the exercise programs for patients with PAD and are automatically generated by the mobile apps. Patients will be prompted to use the exercise function on the mobile apps at least 3 times per week. Once the exercise function is activated, it will extract the steps counts and the walking pace from the WAM during exercise. Patients will be instructed to walk to maximal claudication symptom before stopping, at which point they will press pause on the WAM which will mark the claudication onset time. After the claudication subside, they can resume walking and resume recording on their WAM. Each exercise session will last for 45 minutes excluding rest periods, but the subject can terminate the exercise before the session ends.

The mobile apps and mobile platform are adopted from the HOBBIT-PAD platform prototype that was developed specifically for patients with PAD based on user-centred design. This platform contains patient education information, instruction for exercise, activity record, and embedded messaging function between the patient and the research team about any technical and clinical issue. The source code for this platform is publicly available. Important customization will be made to tailor this mobile health platform for this study, which includes addition of patient education materials on PAD and its management, tips on health eating and lifestyle, and tips on exercise. These materials are adopted from the patient education materials available on the Hospital Authority and the AHA website. This information will be periodically sent to the subject's mobile device as a push notification to help them better understand their disease and to promote independent self-care and healthy lifestyle.