About the Authors

Qiuyan Liao

Affiliation Health Behaviours Research Group, Department of Community Medicine and School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China

Benjamin J. Cowling

Affiliation Infectious Diseases Research Group, Department of Community Medicine and School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China

Wendy Wing Tak Lam

Affiliation Health Behaviours Research Group, Department of Community Medicine and School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China

Richard Fielding

fielding@hku.hk

Affiliation Health Behaviours Research Group, Department of Community Medicine and School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Analyzed the data: QL. Contributed reagents/materials/analysis tools: QL BJC WWTL RF. Wrote the paper: QL BJC WWTL RF.