affiliation not provided to SSRN, University of Oxford - Health Economics Research Centre (HERC), affiliation not provided to SSRN, Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, University of Oxford - Centre for Criminology - University of Oxford, Nanyang Technological University (NTU) - Asian School of the Environment, affiliation not provided to SSRN, Ministry of Health Malaysia, University of Malaya (UM) - Department of Medicine and University of Oxford - Health Economics Research Centre (HERC)