[1] Stellenbosch Univ, Fac Med & Hlth Sci, Div Epidemiol & Biostat, Ctr Evidence Based Hlth Care, Cape Town, South Africa
[2] Sideview, Princes Risborough, England
[3] Univ Split, Sch Med, Split, Croatia
[4] Univ Liverpool Liverpool Sch Trop Med, Dept Clin Sci, Liverpool, Merseyside, England