1. School of Preclinical Medicine, Beijing University of Chinese Medicine, No. 11, Beisanhuan Donglu, Chaoyang District, Beijing 100029, China
2. Center for Applied Statistics, Renmin University of China, 59 Zhongguancun Avenue, Haidian District, Beijing 100872, China
3. School of Statistics, Renmin University of China, 59 Zhongguancun Avenue, Haidian District, Beijing 100872, China
4. School of Public Health, Yale University, 60 College Street, New Haven, CT 06511, USA
5. Department of Basic Theory in Chinese Medicine, Henan University of Traditional Chinese Medicine, Zhengzhou 450008, China