Efficacy and Feasibility of Pain management and Patient Education for Physical Activity in Intermittent claudication (PrEPAID): protocol for a randomised controlled trial

Background: Physical activity (PA) improves functional capacity, quality of life and provides secondary prevention benefits in individuals with peripheral arterial disease (PAD) and intermittent claudication (IC). However, pain and patient lack of knowledge are keys barriers to the uptake of, and adherence to, PA recommendations. This trial will test the efficacy and feasibility of a non-invasive pain management intervention with and without patient education to improve PA in individuals with PAD and IC. Methods: This is a randomised, controlled, assessor blinded feasibility trial with four parallel groups. Eighty adults with PAD and IC will be randomly assigned 1:1:1:1 to Active TENS (transcutaneous electrical nerve stimulation), Placebo TENS, Active TENS + Patient education or Placebo TENS + Patient education groups. All groups will continue to receive usual care over the intervention period. Participants randomized to Active TENS will receive TENS device (preset at 120 Hz, 200µs) and will be instructed to use the device daily at home or elsewhere for six weeks with a patient determined intensity of ‘‘strong but comfortable’’. Placebo TENS group participants will receive the same model of TENS device and instructions for use as those in the active group except that the stimulation dose will be safely altered to produce non-therapeutic, ineffective stimulation. Participants randomised to patient education will receive one-off three-hour workshop of structured group education (4-5 persons in each group) and three 2-weekly phone calls. Efficacy outcomes will be assessed at baseline, after six weeks of intervention and at 3 months follow up. Absolute claudication distance using the Gardner treadmill protocol will be assessed as the primary outcome. Secondary outcomes will assess initial claudication distance, daily PA, and patient reported outcomes including quality of life, pain self-efficacy, depression, disease perception, and walking impairment pain intensity and quality. Feasibility outcomes will assess rates of recruitment, retention and adherence. Focus groups with participants at the end of the trial will explore the acceptability of the interventions. Discussion: This trial will determine the efficacy and feasibility of using a low-cost CE marked non-invasive pain management modality delivered within or without a patient-centred education intervention to improve PA in individuals with PAD and IC.