Article History
Received: 9 November 2020
Accepted: 29 March 2021
First Online: 7 April 2021
Declarations
: This study was purely registry based, as no human participants were recruited or included in experiments. Approval from the University of Pretoria Ethics Committee to conduct a research project with the 2004 to 2008 Johannesburg mortality data was obtained (Ethics reference number 101/2013). Statistics South Africa supplied anonymous cause-specific mortality data of Cape Town, Durban, and Johannesburg for the period 1 January 2006 to 31 December 2010.
: Not applicable.
: Not applicable.
: The authors declare no competing interests.