1. Department of Primary Care and Public Health, Imperial College LondonCharing Cross Campus, London W6 8RP, UK
2. Department of Family Medicine, Taipei City Hospital, Renai BranchTaipei, Taiwan
3. Institute of Preventive Medicine, National Taiwan UniversityTaipei, Taiwan
4. Dr Foster Unit at Imperial College, Department of Primary Care and Public Health, Imperial College LondonLondon EC1A 9LA, UK
5. Non-Communicable Disease Epidemiology Unit, London School of Hygiene and Tropical MedicineLondon WC1E 7HT, UK
6. Department of Medicine, Imperial College LondonChelsea and Westminster Campus, London SW10 9NH, UK