Severe aorto-iliac steno-occlusive atherosclerotic disease is a major cause of morbidity and amputation in patients with peripheral arterial disease. While both open surgical and endovascular revascularisation are standard treatments in this patient group, there is no high-quality randomised evidence to determine which approach offers superior clinical and cost-effectiveness, leading to uncertainty and poor outcomes after intervention.

The EVOCC trial is a national, multicentre, parallel-group, superiority randomised controlled trial comparing open surgery to endovascular revascularisation in patients with symptomatic severe aorto-iliac occlusive disease. A total of 628 participants across 30 NHS sites in the UK will be randomised 1:1 to receive either open surgery or endovascular (minimally invasive) intervention. The primary outcome is amputation-free survival, defined as time to first event (major lower limb amputation or death). Secondary outcomes include mortality, cardiovascular events, hospital readmissions, re-interventions and quality-of-life measures. An internal pilot phase (10 sites, 6-month duration) will assess recruitment feasibility. A QuinteT Recruitment Intervention is integrated into the trial to optimise recruitment.

The trial has received ethical approval from a UK Research Ethics Committee (REC reference: 23/SW/0065; trial registration reference: ISRCTN14591444). Informed consent will be obtained from all participants.

The EVOCC trial is the first RCT assessing the clinical and cost-effectiveness of open vs endovascular revascularisation for severe aorto-iliac disease worldwide. The results will provide robust evidence to inform clinical practice and healthcare policies globally. Results will be disseminated via patient groups, online lay summaries, a trial website, social media, presentations in conferences, a formal scientific publication in a medical journal and direct communications with policymakers across borders.

ISRCTN14591444.

Recent legislation in the UK regarding requirements for new developments to increase biodiversity may have significant implications for the environment and population health. Despite this, relatively little is known regarding the health and social benefits of increasing biodiversity in densely populated urban areas.

This protocol outlines plans for a mixed-method, longitudinal, natural experiment study which will evaluate the planned, biodiversity-focused redevelopment of six small urban parks in Edinburgh, Scotland (UK). Using systematic observation (at baseline, 1 month post-intervention and 1 year post-baseline) and a longitudinal household survey (at baseline and 1 year post-baseline), the primary outcomes of personal well-being, and secondary outcomes of nature connectedness and park usage behaviours, will be assessed, respectively. Consent for data linkage of respondent’s health records will also be sought. Process evaluation will employ semi-structured, qualitative interviews with stakeholders and walk-along interviews with local residents in order to understand implementation processes. Space-related well-being will also be assessed using citizen science approaches.

This study was approved by the University of Edinburgh’s School of Health in Social Sciences ethics committee. This study will provide further evidence for policymakers, the public and researchers of the health and social well-being effects of urban biodiversity interventions. Study findings will be disseminated via public forums such as community workshops and through publication in peer-reviewed journals and presentation at scientific conferences.