1 Department of Family Medicine and Primary Health Care, United Christian Hospital and Tseung Kwan O Hospital, Kowloon East Cluster, Hospital Authority, Hong Kong, China. Email: chowkl2@ha.org.hk.
2 Department of Family Medicine and Primary Health Care, United Christian Hospital and Tseung Kwan O Hospital, Kowloon East Cluster, Hospital Authority, Hong Kong, China.