1. Hong Kong Tuberculosis, Chest and Heart Diseases Association, Hong Kong, China
2. Institute of Applied Health Research, University of Birmingham, Birmingham, UK
3. School of Public Health, The University of Hong Kong, Hong Kong, China
4. Istituti Clinici Scientifici Maugeri, IRRCS, Tradate, Italy, , Email: ccleungpnc@netvigator.com