Table 2

Input parameters used in the extended cost-effectiveness analysis of introducing a sugar-sweetened beverage (SSB) tax in South Africa

InputValueSource
Tax, price and sugar content per litre
of SSB
 Tax (ZAR cents)2.21 cents/g of sugar over 4 g/100 mLNational Treasury11 12
 Sugar content per litre (g)106 gNational Treasury11 12
 Price per litreZAR11.45National Treasury11 12
Mortality due to diabetes mellitus (T2DM) as percentage of all deaths5.4% Statistics South Africa
Relative risk of T2DM by age group per each unit
increase in BMI
 <301.37IHME51
 30–341.34
 35–391.32
 40–441.29
 45–491.27
 50–541.24
 55–591.22
 60–641.20
 65–691.18
 70–741.15
 75–791.13
 80+1.10
Average proportion of healthcare costs paid as OOP payment by income quintile
 Quintile 121%NIDS wave 447, NDoH,
authors’ calculations
 Quintile 218%
 Quintile 341%
 Quintile 456%
 Quintile 582%
Income per capita quintiles in ZAR
 Quintile 1<6486 (US$525)NIDS wave 447, NDoH, authors’ calculations
 Quintile 26486 to 13 818
(US$525–US$1119)
 Quintile 313 819–28 091
(US$1119–US$2275)
 Quintile 428 092–71 478
(US$2275–US$5788)
 Quintile 5>71 478
(US$5788)
Labour force participation rate
 Quintile 10.51GHS68,
authors’ calculations
 Quintile 20.53
 Quintile 30.61
 Quintile 40.71
 Quintile 50.78
Absenteeism and presenteeism ratios
 Number of excess sick days in a year8.6Bommer et al 57 based on data from Guariguata et al 56
 Productivity shortfall0.6%Bommer et al 57 based on data from Seuring et al 58
  • US$1=ZAR12.35 (as of May 2018). Source: South Africa Revenue Service (SARS) available at http://tools.sars.gov.za/rex/Rates/Default.aspx.

  • BMI, body mass index; GHS, General Household Survey; IHME, Institute for Health Metrics and Evaluation; NDoH, National Department of Health; NIDS, National Income Dynamics Study; OOP, out-of-pocket; T2DM, type 2 diabetes mellitus; ZAR, South African rand.