Clinical and cost-effectiveness of individualised exercises and foot orthoses in the treatment of plantar heel pain: a randomised multi-arm multi-stage (MAMS) adaptive trial (TReatments of Exercise AnD Orthotics for plaNtar heel pain (TREADON))

RESEARCH QUESTION: What is the clinical and cost-effectiveness of prefabricated foot orthoses and/or individualised exercises plus self-management advice (SMA) compared with SMA alone to treat adults with plantar heel pain (PHP) in primary care? BACKGROUND: PHP is the most common soft tissue foot complaint and impairs mobility, physical function, ability to work, and quality of life. Initial treatment is with analgesia and advice about rest, footwear, heel pads, weight loss and exercises. Referral to a podiatrist or physiotherapist is advised if symptoms are severe or persist. Although PHP is commonly said to resolve over 1-2 years, symptoms often become chronic. Systematic reviews highlight a need for high-quality randomised controlled trials (RCTs) of orthoses and exercises for PHP. OBJECTIVES: To examine whether a SMA booklet plus prefabricated foot orthoses and/or individualised exercises leads to greater improvement in pain (primary outcome), first step pain, foot function, patient global rating of change, pain self-efficacy, illness perceptions, and ability to work than a SMA booklet alone in adults with PHP. We will assess recruitment, intervention fidelity, adherence and follow-up in a 6-month internal pilot and examine cost-effectiveness and treatment adherence and satisfaction. METHODS: Design: multi-centre four-arm two-stage adaptive parallel-group RCT with internal pilot Setting: primary care. Treatment in NHS physiotherapy/podiatry services Duration: 51 months Target population: adults aged 18 years and over with PHP Participants will be randomised 1:1:1:1 to one of: • SMA booklet (control) • SMA booklet + pre-fabricated foot orthoses • SMA booklet + individualised exercises • SMA booklet + individualised exercises and pre-fabricated foot orthoses. Outcomes will be collected by SMS text-message (weekly during weeks 1-12, monthly thereafter) and questionnaires at 12 weeks and 6 and 12 months. Primary outcome: change in PHP intensity (0-10 numeric rating scale (NRS)) between baseline and the average over weeks 6-12. Sample size: Up to maximum of 696 participants to detect an effect size 0.3 in average pain NRS over weeks 6-12 in at least one intervention arm against control (90% probability, 1-sided 5% significance, 20% loss to follow-up). The expected sample size ranges from 490-610. Adaptive design: an interim analysis will be performed when half of the target sample size, 348 participants, have completed the primary outcome, allowing futile interventions to be dropped or the trial stopped early (for efficacy or futility). TIMELINE: Months 0-9: set-up. 10-16: internal pilot. 10-33: recruitment. 10-36: intervention delivery. 10-45: follow-up. 25-26: interim analysis. 46-51: data cleaning, analysis, dissemination, final report. ANTICIPATED IMPACT AND DISSEMINATION: New evidence will be provided for patients with PHP and their GPs, physiotherapists and podiatrists which will directly inform treatment decisions. We will make results freely available to patients, clinicians and commissioners, by publishing in peer-reviewed journals, on our website, through social media, and presenting at scientific meetings. Our PPIE group will help us translate findings into easily understandable messages and disseminate the results to the wider public. We will work closely with the NIHR Applied Research Collaborations, AHSNs, professional/specialist societies, royal colleges and charities to ensure wide dissemination and uptake.