# 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

## TL;DR

This study will test if exercises and foot orthoses, alone or together, are more effective and cost-effective than self-management advice alone for treating heel pain in adults.

## Contribution

The trial introduces a novel adaptive design to evaluate individualized interventions for plantar heel pain in a large-scale, real-world setting.

## Key findings

- The trial will assess pain intensity changes over 6–12 weeks using a numeric rating scale.
- Adaptive interim analysis will guide early stopping or intervention continuation based on pain reduction.
- Cost-effectiveness and long-term outcomes will be evaluated up to 12 months.

## Abstract

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.

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.

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.

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.

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

To show whether exercises and/or foot orthoses (shoe insoles) provide more pain relief for adults with plantar heel pain than a self-management advice booklet alone, and whether this is good value for money for the NHS.

Pain under the heel (plantar heel pain, PHP) affects 1 in 10 adults. It makes walking and everyday tasks, including work, difficult. Most people who consult general practice are given pain medication and advice, yet symptoms often continue. In our pilot and feasibility trial, exercises and foot orthoses showed promise for improving pain and function, but a larger trial is needed to confirm this.

In this randomised controlled trial, up to 696 adults with PHP will be given a self-management advice booklet and allocated by chance to one of four treatments: exercises, foot orthoses, combined exercises and foot orthoses, or no additional treatment. Participants will be sent weekly text-messages or receive brief phone calls, to collect pain scores for up to 12 weeks and then monthly from 3-12 months, plus questionnaires at 3, 6 and 12 months. Half-way through the trial, only treatments that are reducing pain will continue to be offered and the trial will stop early if one treatment is clearly better.

Patient representatives will support the trial and helped write this summary. Five people with PHP took part in a workshop to help with trial design. For example, they helped decide how often pain should be measured. We will involve people with PHP to assist with our recruitment strategy and help us interpret the findings, develop easily understandable messages and publicise them widely.

We will present findings at healthcare conferences, in medical journals, on relevant websites, through social media, and general practice, physiotherapy and podiatry networks. The results will be provided to participants.