1. Hypertension in Africa Research Team (HART),North-West University (Potchefstroom Campus), Potchefstroom 2531, South Africa
2. MRC Research Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom 2520, South Africa
3. School of Population Health, The George Institute for Global Health, University of New South Wales, Sydney, NSW 2042, Australia
4. School of Cardiovascular and Metabolic Health, University of Glasgow, Glasgow G12 8QQ, U.K.
5. Mosaiques Diagnostics GmbH, Hannover D-30659, Germany