Supported Inspiratory Muscle training (SIMT) for People with chronic obstructive puLmonary disease (COPD) who have dEclined pulmonary Rehabilitation (PR): A pilot randomised controlled trial (RCT) and process evaluation. Brief Title: SIMPLER

Background: Inspiratory Muscle Training (IMT) may appeal to those who decline pulmonary rehabilitation (PR) and may enable future PR participation.

A multicentre randomised controlled trial (RCT) is needed but there are uncertainties to address to ensure the feasibility and value of this RCT.

Research questions: Is a multi-centre RCT feasible to evaluate whether SIMT: Is a viable treatment option for those who decline PR? Increases PR uptake for people who have initially declined?

Aims: To conduct a feasibility study to inform a prospective multicentre RCT of Supported IMT for people with COPD who decline PR Objectives: Assess recruitment rates and attrition using a pilot RCT Assess acceptability of outcome measures and availability of healthcare utilisation data Explore the addition of support to enhance adherence with IMT Explore the feasibility and acceptability of IMT within a process evaluation Estimates of means and variance for continuous outcomes Calculate sample size for definitive RCT Refine intervention and RCT processes Design: A mixed methods feasibility study, in a parallel convergent design, consisting of a concurrent pilot RCT and process evaluation.

Method: Workstream One: Pilot RCT (MONTHS 13-36) 34 people with COPD who decline PR within two Trusts (Sheffield and Rotherham) will be recruited over 15 months. Participants will be offered randomisation to receive Supported IMT or sham IMT for nine months.

Group 1 Supported IMT (SIMT): IMT using the Powerbreathe Kinetic device (Powerbreathe) supervised weekly for the first eight weeks, then unsupervised for a further 31 weeks. Goals, Action Planning and Feedback will be used to support IMT adherence (hence it is 'Supported IMT'). Feedback will include session adherence, training quality and weekly inspiratory muscle strength.

Group 2 Sham SIMT: As per Group 1, but suboptimal intensity and modified feedback (without weekly inspiratory muscle strength). Outcomes: Progression criteria for a future RCT. Early outcomes: Inspiratory muscle strength and IMT adherence. Intermediate outcomes: Health related Quality of Life (HRQOL), dyspnoea, and physical activity.

Long term outcomes: PR uptake and healthcare utilisation.

Workstream Two: Process Evaluation (MONTHS 17-40) A process evaluation will include semi-structured interviews with 10-15 intervention users at eight-week and nine-month assessments to explore the acceptability of IMT and 2-6 intervention providers at the end of the intervention period to explore the feasibility of IMT delivery.

Questionnaires will be given to all participants at baseline, eight-week and nine-month assessments to evaluate acceptability of the intervention and study process.

Workstream 3 Refinement of intervention and RCT processes (MONTHS 39-45) If warranted following the findings of this study, the intervention and RCT processes will be refined to feed into the design of a full multicentre RCT.

Anticipated impact: Informing a full RCT to establish if IMT improves outcomes for people with COPD who decline PR, enhances PR uptake and is cost-effective.

Dissemination: Feedback to study participants, patient and public involvement (PPI) groups and commissioners, conference presentations, peer-reviewed journal articles, relevant social media platforms and engagement with non-academic audiences.