Corresponding authors:
Guowei Li, PhD, MSc, MBBS
CCEM, Guangdong Second Provincial General Hospital, 466 Newport Middle
Road, Haizhu District, Guangzhou 510317, Guangdong Province, China
Department of Health research methods, Evidence, and Impact (HEI),
McMaster University, 1280 Main St West, Hamilton, ON, Canada L8S 4L8
Telephone: 86-020-89169025; Fax: 86-020-89168021
E-mail: lig28@mcmaster.ca
and
Junzhang Tian, MD
CCEM, Guangdong Second Provincial General Hospital, 466 Newport Middle
Road, Haizhu District, Guangzhou 510317, Guangdong Province, China
Telephone: 86-020-89169016; Fax: 86-020-89168025
E-mail: zhanggd2h@163.com