Pursuing Reduction in Fatigue After COVID-19 via Exercise and Rehabilitation (PREFACER): a protocol for a randomised feasibility trial.

INTRODUCTION: Over 777 million COVID-19 infections have occurred globally, with data suggesting that 10%-20% of those infected develop Long COVID. Fatigue is one of the most common and disabling symptoms of Long COVID. We aim to assess the feasibility and safety of a new, remotely delivered, multimodal rehabilitation intervention, paced to prevent post-exertional malaise (PEM), to support the conduct of a future, definitive randomised trial. METHODS AND ANALYSIS: We will conduct a randomised, two-arm feasibility trial (COVIDEx intervention vs usual care). Sixty participants with Long COVID will be recruited and randomised prior to giving informed consent under a modified Zelen design using 1:1 allocation with random permuted blocks via central randomisation to receive either the COVIDEx intervention or usual care. The 50-minute, remotely delivered, COVIDEx intervention will occur twice weekly for 8 weeks. All participants will wear a non-invasive device throughout their entire study participation, to track heart rate, blood oxygen saturation, steps, sleep and monitor PEM. The primary feasibility objectives will be recruitment rates, intervention fidelity, adherence, acceptability (intervention and design), retention, blinding success and outcome completeness. Secondary objectives will include refined estimates for the standard deviation and correlation between baseline and follow-up measurements of fatigue. Feasibility and clinical outcomes will be collected at baseline, 4, 8, 12 and 24 weeks. Qualitative interviews with participants and physiotherapists will explore intervention acceptability and barriers/facilitators. ETHICS AND DISSEMINATION: Ethical approval for this study was obtained by the Western University Health Sciences Research Ethics Board (REB# 123902). Dissemination plans include sharing of trial findings at conferences and through open access publications and patient/community channels. TRIAL REGISTRATION NUMBER: NCT06156176.