1. Ha Kwai Chung General Outpatient Clinic, Department of Family Medicine and Primary Health Care, Kowloon West Cluster, Hospital Authority, 77 Lai Cho Road, Kwai Chung, N.T., Hong Kong
2. Department of Family Medicine and Primary Care, The University of Hong Kong, 3/F., 161 Main Street, Ap Lei Chau Clinic, Ap Lei Chau, Hong Kong
3. Department of Medicine, The University of Hong Kong, Room 405B, 4/F, Professorial Block, Queen Mary Hospital, 102 Pok Fu Lam Road, Pok Fu Lam, Hong Kong