Ryan Essex1, Ishanka Talagala2, Olamide Dada3, Mala Rao4. 1. The University of Greenwich, Old Royal Naval College, Greenwich, London SE10 9LS, UK r.w.essex@gre.ac.uk. 2. Ministry of Health, Colombo 10, Sri Lanka. 3. School of Medicine, Cardiff University, Cardiff, UK. 4. Ethnicity and Health Unit, Department of Primary Care and Public Health, Imperial College London, UK.