Venous Thrombo-Embolism Risk After Emergency Department and Same Day Emergency Care Discharge: A Retrospective Observational Study of Adult Patients Attending Two Hospital Sites v2

This protocol outlines a retrospective observational study examining venous thromboembolism (VTE) risk in patients discharged from Emergency Department (ED) and Same Day Emergency Care (SDEC) pathways over a three-year period. Data will be obtained under local NHS Trust information governance approvals and data sharing agreements, with case ascertainment following established coding and audit procedures. All data handling will comply with GDPR and NHS governance requirements, with pseudonymised records used for analysis. Ethical approval will be sought from the appropriate NHS Research Ethics Committee. As a retrospective study using routinely collected data, individual patient consent is not required. Patient and public involvement was provided by a contributor with whom one of the researchers had previously collaborated, alongside input from clinical and organisational stakeholders. Together, these perspectives ensured that the study objectives are both patient-centred and operationally meaningful. The study has limitations, including constraints inherent to retrospective design, risks of missing or incomplete data, and limited generalisability beyond a single Trust setting. These will be acknowledged when interpreting results. Dissemination will include a peer-reviewed publication and presentation at a professional conference, alongside local feedback to the host NHS Trust and a plain-English summary for patient and public audiences. The anticipated impact is to inform local policy on VTE risk management in non-admitted emergency pathways and contribute to wider NHS discussions on enhanced SDEC models and VTE surveillance.