About the Authors

Yue Ma

Affiliation West China School of Public Health, Sichuan University, Chengdu 610041, China

Fei Yin

Affiliation West China School of Public Health, Sichuan University, Chengdu 610041, China

Tao Zhang

Affiliation West China School of Public Health, Sichuan University, Chengdu 610041, China

Xiaohua Andrew Zhou

Affiliation Department of Biostatistics, School of Public Health, University of Washington, Seattle 98195, United States of America

Xiaosong Li

publichealth.scu@gmail.com

Affiliation West China School of Public Health, Sichuan University, Chengdu 610041, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: YM TZ FY XL. Performed the experiments: YM. Analyzed the data: YM. Wrote the paper: YM XAZ.