Clinical and cost-effectiveness of individualised exercises and foot orthoses in the treatment of plantar heel pain: protocol for the TREADON randomised multi-arm multi-stage adaptive trial.

Abstract

Background: Plantar heel pain (PHP) is the most common soft tissue foot condition and impairs mobility, physical function, ability to work, and quality of life. Systematic reviews highlight a need for high-quality randomised controlled trials (RCTs) of exercises and orthoses for PHP.

Objectives: To determine the clinical and cost-effectiveness of individualised exercises and/or prefabricated foot orthoses plus self-management advice (SMA) compared to SMA alone in adults with PHP.

Methods: A multi-centre four-arm two-stage adaptive parallel-group RCT with internal pilot. Up to 696 participants aged ≥18 years with PHP will be identified from general practice, physiotherapy/podiatry referrals and self-referral, and randomised 1:1:1:1 to: (1) SMA (control), (2) SMA plus individualised exercises, (3) SMA plus prefabricated foot orthoses, or (4) SMA plus individualised exercises and prefabricated foot orthoses. Outcomes will be collected by SMS text-message (weekly during weeks 1-12, monthly during months 4-12) and questionnaires at 12 weeks and 6 and 12 months. The primary outcome is change in PHP intensity (0-10 numeric rating scale) between baseline and the average over 6-12 weeks. Interim analysis when 348 participants have completed the primary outcome assessment will inform adaptation, where interventions may be dropped or the trial stopped early (for efficacy or futility). The main between-group comparison for the primary outcome will be undertaken using linear mixed modelling. Secondary outcomes will examine i) short-term pain trajectories over weeks 1-12, ii) pain at 6 and 12 months, and monthly from 3-12 months, iii) first step pain, physical function, global rating of change, pain self-efficacy, illness perceptions, ability to work, and treatment satisfaction at 12 weeks, 6 and 12 months, iv) cost-effectiveness. Patient and public partner involvement is embedded throughout.

Discussion: The TREADON multi-arm multi-stage RCT will provide new evidence on the clinical and cost-effectiveness of individualised exercises and prefabricated foot orthoses for people with PHP.

Trial registration: ISRCTN 12418153. Registration date 06 December 2022 https://doi.org/10.1186/ISRCTN12418153.