Funding for this research was provided by:
South African Medical Research Council (MRC-RFA-UFSP-01-2013/ VMH Study)
Text and Data Mining valid from 2019-11-08
Received: 11 July 2019
Accepted: 15 October 2019
First Online: 8 November 2019
Ethics approval and consent to participate
: Ethical approval was obtained from the Ethics Committees of the Cape Peninsula University of Technology and Stellenbosch University (NHREC:REC-230 408-014, CPUT/HWS-REC 2015/H03 and N14/01/003). Participants provided written consent to participate in the study.
: Not applicable.
: The authors declare that they have no competing interests.