1 Sections on Cardiovascular Medicine and Geriatrics/Gerontology, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA.
2 Division of Geriatric and Palliative Medicine, University of Michigan, Ann Arbor, Michigan, USA.
3 Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
4 Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA.