1. Mater Misericordiae University Hospital; Department of Vascular Surgery; Eccles Street Dublin Ireland
2. University of Edinburgh; Usher Institute of Population Health Sciences and Informatics; Edinburgh UK EH8 9AG
3. Royal Victoria Hospital; Belfast Vascular Centre; Belfast Health & Social Care Trust Belfast Northern Ireland UK BT12 6BA
4. Centre for Public Health, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast; University Road Belfast Northern Ireland UK