Hypertension education and adherence in South Africa: a cost-effectiveness analysis of community health workers

BACKGROUND To determine whether training community health workers (CHWs) about hypertension in order to improve adherence to medications is a cost-effective intervention among community members in South Africa. METHODS We used an established Markov model with age-varying probabilities of cardiovascular disease (CVD) events to assess the benefits and costs of using CHW home visits to increase hypertension adherence for individuals with hypertension and aged 25-74 in South Africa. Subjects considered for CHW intervention were those with a previous diagnosis of hypertension and on medications but who had not achieved control of their blood pressure. We report our results in incremental cost-effectiveness ratios (ICERs) in US dollars per disability-adjusted life-year (DALY) averted. RESULTS The annual cost of the CHW intervention is about $8 per patient. This would lead to over a 2% reduction in CVD events over a life-time and decrease DALY burden. Due to reductions in non-fatal CVD events, lifetime costs are only $6.56 per patient. The CHW intervention leads to an incremental cost-effectiveness ratio of $320/DALY averted. At an annual cost of $6.50 or if the blood pressure reduction is 5 mmHg or greater per patient the intervention is cost-saving. CONCLUSIONS Additional training for CHWs on hypertension management could be a cost-effective strategy for CVD in South Africa and a very good purchase according to World Health Organization (WHO) standards. The intervention could also lead to reduced visits at the health centres freeing up more time for new patients or reducing the burden of an overworked staff at many facilities.