1. University of Edinburgh; Public Health Sciences; Teviot Place Edinburgh UK EH8 9AG
2. University of Stirling; Department of Nursing and Midwifery; Stirling Scotland UK FK9 4LA
3. University of Edinburgh; Wolfson Unit for the Prevention of Peripheral Vascular Disesases; Teviot Place Edinburgh Scotland UK EH8 9AG
4. London School of Hygiene and Tropical Medicine; Keppel Street London UK WC1E 7HT