1. School of Public Health, The University of Hong Kong, Hong Kong SAR, China
2. Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA
3. Center for Evidence Synthesis in Health, Brown University School of Public Health, Providence, RI, USA
4. Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China
5. UK Small Area Health Statistics Unit, MRC-PHE Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK
6. Elderly Health Service, Department of Health, Hong Kong SAR, China