[1] South African Med Res Council, Hlth Syst Res Unit, Cape Town, South Africa
[2] Tampere Univ, Fac Social Sci, Tampere, Finland
[3] Karolinska Inst, Dept Global Publ Hlth, Stockholm, Sweden
[4] South African Med Res Council, Hlth Syst Res Unit, Durban, South Africa
[5] Univ KwaZulu, Natal Nelson R Mandela Sch Med, Ctr AIDS Programme Res South Africa, Durban, South Africa