[1] Univ KwaZulu Natal, Fac Hlth Sci, Sch Med, Dept Internal Med, Pietermaritzburg, South Africa
[2] Univ KwaZulu Natal, Fac Hlth Sci, Sch Med, Dept Internal Med, Durban, South Africa
[3] Natl Hlth Serv NHS England, Joint Royal Coll Phys Training Board, Dept Internal Med, Chelmsford, Essex, England
[4] Northdale Hosp, KwaZulu Natal Dept Hlth, Pietermaritzburg, South Africa
[5] Univ KwaZulu Natal, Sch Nursing & Publ Hlth, Dept Family Med, Durban, South Africa