HIDDEN2: Study protocol for the hospital deep vein thrombosis detection study in patients with cancer receiving palliative care

INTRODUCTION: Medical patients, admitted acutely to hospital, are at risk of venous thromboembolism (VTE). Clinical guidelines advise thromboprophylaxis prophylaxis for those at high risk of VTE. VTE is a common sequela of cancer, but guidelines take little consideration of cancer as an independent risk factor and their utility in palliative care patients is unclear. The hospice inpatient deep vein thrombosis (DVT) detection study (HIDDen) reported a 28% prevalence of asymptomatic iliofemoral DVT in hospice patients of poor performance status (PS) and prognosis, calling into question the utility of thromboprophylaxis in the palliative care setting. However, the majority of cancer inpatients receiving palliative care are admitted to hospital through the acute medical setting, yet their risk factors for VTE may differ from those admitted to hospices. OBJECTIVE: To better understand the prevalence and behaviours of VTE in patients with cancer receiving palliative care who are admitted as an acute medical emergency. DESIGN: Multicentre, observational cohort study. SETTING: Secondary care acute hospitals in South Wales, UK. PATIENTS: We plan to recruit 232 patients≥18 years old with a diagnosis of incurable cancer, and/or receiving palliative or best supportive care who are admitted acutely to hospital. Patients will be followed up for a maximum of 6 months following registration. PRIMARY OUTCOME: Presence of lower extremity DVT. SECONDARY OUTCOMES: Symptom burden attributed to DVT or pulmonary embolism, patient PS, patient demographics and development of new VTE within 90 days of registration. ANALYSIS: The study statistical analysis plan will document analysis, methodology and procedures. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Wales Research Ethics Committee, reference 22/WA/0037 (IRAS 306352)—the main trial results will be analysed as soon as practically possible and the publication shared with investigators and on sponsor website; applications to access trial data will be subject to sponsor review process.