Received: 18 January 2019
Accepted: 28 October 2019
First Online: 9 November 2019
Ethics approval and consent to participate
: Approval was obtained from the Human Research Ethics Committee (HREC) of Stellenbosch University (protocol number S15/02/020) and the Chief Executive Officer of Tygerberg Hospital to conduct this study. In view of the retrospective nature of the study, waiver of patient consent was approved by the HREC.
: Not Applicable.
: The authors declare that they have no competing interests. The results presented in this article have not been published previously in whole or part, except in abstract format.