About the Authors

Qiuyan Liao

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

Benjamin Cowling

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

Wing Tak Lam

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

Man Wai Ng

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

Richard Fielding

fielding@hkusua.hku.hk

Affiliation Health Behaviour Research Group, Department of Community Medicine, 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. Wrote the paper: QL. Planned the study: RF, BC. Guided data analysis: RF BC WTL. Interpretation of the data: RF BC WTL. Made critical revisions of the manuscript: RF, BC. Contributed to the design of the survey instrument: RF QL BC WTL MWN. Coordinated the telephone interview: MWN. Managed the dataset: MWN.