1. Department of Health Sciences, University of York, Heslington, York, UK
2. Department of Economics, University of Dhaka, Social Science Building, Nilkhet, Dhaka, Bangladesh
3. Centre for Medical Informatics, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, Medical School, Teviot Place, Edinburgh, UK
4. Department of Public Health, Leeds City Council, Leeds, UK