a1 Division of Maternal and Child Health, Department of Paediatrics, University of KwaZulu-Natal, Durban, P/Bag 7, Congella 4013, South Africa
a2 Center for International Health, University of Bergen, Bergen, Norway
a3 South African TB Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
a4 School of Child Health, University of Cape Town, Cape Town, South Africa
a5 i3 Research, Maidenhead, UK
a6 Mpilonhle, Mtubatuba, South Africa
Objective To describe the cost of diarrhoeal illness in children aged 6–24 months in a rural South African community and to determine the threshold prevalence of stunting at which universal Zn plus vitamin A supplementation (VAZ) would be more cost-effective than vitamin A alone (VA) in preventing diarrhoea.
Design We conducted a cost analysis using primary and secondary data sources. Using simulations we examined incremental costs of VAZ relative to VA while varying stunting prevalence.
Setting Data on efficacy and societal costs were largely from a South African trial. Secondary data were from local and international published sources.
Subjects The trial included children aged 6–24 months. The secondary data sources were a South African health economics survey and the WHO-CHOICE (CHOosing Interventions that are Cost Effective) database.
Results In the trial, stunted children supplemented with VAZ had 2·04 episodes (95 % CI 1·37, 3·05) of diarrhoea per child-year compared with 3·92 episodes (95 % CI 3·02, 5·09) in the VA arm. Average cost of illness was $Int 7·80 per episode (10th, 90th centile: $Int 0·28, $Int 15·63), assuming a minimum standard of care (oral rehydration and 14 d of therapeutic Zn). In simulation scenarios universal VAZ had low incremental costs or became cost-saving relative to VA when the prevalence of stunting was close to 20 %. Incremental cost-effectiveness ratios were sensitive to the cost of intervention and coverage levels.
Conclusions This simulation suggests that universal VAZ would be cost-effective at current levels of stunting in parts of South Africa. This requires further validation under actual programmatic conditions.
(Received December 03 2012)
(Revised June 22 2013)
(Accepted July 08 2013)