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 and 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 key 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 randomised to Active TENS will receive a TENS device (preset at 120 Hz,
200 μs) and will be instructed to use the device daily at home or elsewhere for 6 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 a one-off 3-h workshop of
structured group education (four to five persons in each group) and three sets of twice-weekly phone calls. Efficacy
outcomes will be assessed at baseline, after 6 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 with or without a patient-centred education intervention to improve PA in individuals
with PAD and IC.
Trial registration: ClinicalTrials.gov, NCT03204825. Registered on 2 July 2017.