Compression hosiery to avoid post-thrombotic syndrome (CHAPS) protocol for a randomised controlled trial (ISRCTN73041168)

This work was supported by the National Institute for Health Research (NIHR), Health Technology Assessment Programme, project number 17/147/47. The HTA Programme is funded by the NIHR, with contributions from the Chief Scientist Office in Scotland and National Institute for Social Care and Health Research in Wales and the Health and Social Care R&D Division, Public Health Agency in Northern Ireland. Sponsor: Imperial College London.Introduction Up to 50% of patients develop post-thrombotic syndrome (PTS) after an above knee deep vein thrombosis (DVT). The aim of the study was to determine the effect of graduated compression stockings in preventing PTS after DVT. Methods and analysis Pragmatic, UK multicentre randomised trial in adults with first above knee DVT. The standard of care arm is anticoagulation. The intervention arm will receive anticoagulation plus stockings (European class II, 23-32 mm Hg compression) worn for a median of 18 months. The primary endpoint is PTS using the Villalta score. Analysis of this will be through a time to event approach and cumulative incidence at median 6, 12 and 18 months. An ongoing process evaluation will examine factors contributing to adherence to stockings to understand if and how the behavioural interventions were effective. Ethics and dissemination UK research ethics committee approval (reference 19/LO/1585). Dissemination though the charity Thrombosis UK, the Imperial College London website, peer-reviewed publications and international conferences.National Institute for Health Research (NIHR) 17/147/47National Institute for Health Research (NIHR)Chief Scientist Office in ScotlandNational Institute for Social Care and Health Research in WalesHealth and Social Care R&D Division, Public Health Agency in Northern IrelandImperial College Londo