University College London - Department of Epidemiology and Public Health, University of Liverpool - Department of Public Health, Policy and Systems, Institute for Fiscal Studies (IFS), Sun Yat-sen University (SYSU) - Department of Medical Statistics and Epidemiology, Sun Yat-sen University (SYSU) - Department of Medical Statistics and Epidemiology, University College London - Department of Epidemiology and Public Health, Institute for Fiscal Studies (IFS), University College London - Division of Psychiatry, University College London - Department of Mental Health of Older People, Sun Yat-sen University (SYSU) - Department of Medical Statistics and Epidemiology and University College London - Department of Epidemiology and Public Health