STEPFORWARD: A randomised controlled trial and economic evaluation of the impact of a hydraulic self-aligning ankle-foot on quality of life for patients with a below-knee amputation who have limited mobility

RESEARCH QUESTION Does a flexible prosthetic foot, that uses a hydraulic self-aligning mechanism, improve quality-of-life (QOL) for patients with limited mobility due to a below-knee amputation and represent value for money for the NHS? BACKGROUND Each year, more than 2,000 below-knee amputations are performed in the UK. Mostly, these patients are aged over 50 years, had their amputation due to peripheral arterial disease or diabetes and manage comorbidities alongside their amputation. They are usually categorised as having “limited mobility” in the community. Most of these patients are prescribed a prosthesis with a rigid foot designed for level walking and standing, with limited functionality. They are often dissatisfied with their prosthesis because walking is difficult and they fall more often, which reduces their QOL. Other prosthetic feet, that are flexible and self-align to slopes, are commercially available but seldom prescribed to users with limited mobility on the NHS because they are more costly and their effectiveness is unproven. We undertook a feasibility study that indicated flexible feet enhanced QOL and walking for patients with limited mobility. A definitive trial is now required to guide clinical decision-making for prosthetic feet. AIM To undertake a randomised controlled trial (RCT) and economic evaluation of a flexible foot compared to a usual care rigid foot for below-knee amputees with limited mobility. METHODS STEPFORWARD is a pragmatic multicentre RCT with embedded pilot and process evaluation. 266 below-knee amputees with limited mobility will be randomised in a 1:1 ratio, stratified by prosthetics site and prosthetic experience, to receive a flexible foot (intervention) or keep their rigid foot (control). The only difference between the groups will be the foot; all participants will have access to usual care. The primary outcome is QOL (EQ5D5L) at 12 months. Secondary outcomes include number of falls, walking, functional mobility (incl. 7-day step count, functional walking tests), prosthesis use and comfort, mental health and healthcare resource use measured every 3 months for 1 year. We will compare costs and consequences (including EQ5D5L) in intervention and control arms over 12 months and extend to longer term costs and QOL to enable an economic evaluation over a lifetime horizon. DELIVERY TIMELINE Timeline in months (M) informed by recruitment rates M0-5 Study set-up, ethics, contracts & approvals M6-17 Internal pilot. Staggered site opening (2-3 sites/month over 4 months); recruitment rate: 1-2 participants/site/month M18 Evaluate internal pilot (n=143 recruited, n=59 @ 6-month follow-up), STOP/GO decision M30 Full trial recruitment (target n=266) M42 Last participant follow-up M42-48 data cleaning, statistical and health economics analyses, reports, dissemination, stakeholder event ANTICIPATED IMPACT AND DISSEMINATION STEPFORWARD will be the first definitive clinical trial involving prosthetics therapies comparing prosthetic feet. We will involve PPI advisors in our project management and dissemination. Our findings will inform patients and NHSE commissioners for prosthetics prescription policies and future prescription protocols. We plan to disseminate to a wide group of stakeholders through academic publications, presentations and hosting an event with policy-makers, clinicians, service centre managers, patient groups and charities to translate the findings into clinical practice.