[1
]
Department of Health Administration, School of Public Health, Sun Yat-sen University,
Guangzhou 510080, China and.
[2
]
Department of Health Policy and Management, Primary Care Policy Center, Bloomberg
School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
[3
]
Department of Health Policy and Management, Primary Care Policy Center, Bloomberg
School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA. lshi@jhsph.edu.