Key considerations for digital decentralised clinical trials from a feasibility study assessing pacing interventions for long COVID.

Post COVID-19 condition or long COVID is highly prevalent and often debilitating, with key symptoms including fatigue, breathlessness, and brain fog. There is currently a lack of evidence-based treatments for this highly complex syndrome. There is a need for clinical trial platforms to rapidly evaluate nonpharmacological treatments to support affected individuals with symptom management. We co-produced a mixed methods feasibility study to evaluate a multi-arm digital decentralised clinical trial (DCT) platform to assess non-pharmacological interventions for Long COVID, using pacing interventions as an exemplar. The study demonstrated that the platform was able to successfully e-consent participants, randomise them into one of four intervention arms, capture baseline data, and capture outcomes relevant to a health economic evaluation. The study also highlighted several challenges, including difficulties with recruitment, imposter participants, and high attrition rates. We highlight how these challenges can potentially be mitigated to make a fully powered DCT more feasible.