Professor Daniel Horner

Researchers secure £3m NIHR funding for new blood clot prevention study

A new £3 million study will be the UK’s largest trial in thromboprophylaxis.

The NIHR-funded study named Thromboprophylaxis in Lower limb Immobilisation (TiLLI) aims to compare different methods of pharmacological thromboprophylaxis – medications used to prevent blood clots – for patients with temporary lower limb (leg) immobilisation after injury to determine their clinical and cost effectiveness.

The five-year programme is being led by Professor Xavier Griffin, Clinical Professor in Orthopaedics at Queen Mary University of London, and Honorary Consultant Orthopaedic Surgeon at Barts Health NHS Trust and Professor Daniel Horner, Consultant in Emergency and Critical Care Medicine at Northern Care Alliance NHS Foundation Trust and honorary clinical professor at The University of Manchester, UK.

Approximately 70,000 people are immobilised after injury every year in the UK. This can lead to venous thromboembolism (VTE), a condition where blood clots form in the veins, and may develop into serious conditions such as deep vein thrombosis (DVT) or pulmonary embolism. Temporary lower limb immobilisation (plaster cast, walking boot or rigid splint) and injury are combined risk factors for someone developing VTE. Many people who survive VTE suffer from longer term physical or psychological complications.


Luckily, VTE in lower limb immobilisation is potentially preventable through early prophylaxis with anticoagulant medication, which helps keep blood flowing smoothly and prevent clot formation. However, the risk of VTE varies widely from person to person, and there are multiple drugs available.

Currently, there is no high-quality evidence comparing different methods of pharmacological thromboprophylaxis for patients at high risk of VTE and limited evidence of the benefits and risks of any prophylaxis for patients at low risk of VTE. This trial will address this evidence gap by comparing the clinical and cost effectiveness of various anticoagulant drugs and therapies. It will involve up to 10,000 patients across 30 hospitals in the UK.

Professor Horner said: “We are delighted to secure funding for this research question, which has been nationally prioritised by patients and clinical teams in emergency care. This trial will identify the best strategy to reduce blood clots in this population and provide a solid evidence base for future guidance.”

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