Abstract 046: Spatial Variation of Predictors of Hypertension in Sub-Saharan Africa: A Case Study of South-Africa
Sub-Saharan Africa (SSA) is a region of striking socio-economic and demographic diversities, characterized by an ongoing epidemiologic transition. Recent work shows that hypertension is of public health importance in SSA, particularly in urban areas, with evidence of considerable under-diagnosis, poor management and lack of communitywide preventive strategies. Our objective was to examine the spatial variation of predictors of hypertension at the province-level in South Africa, after accounting for individual risk factors such socio-demographics, lifestyle, and chronic co-morbidities. Our analysis was based on the 1998 South African Health and Demographic Survey (HDS), including 13,827 men and women aged 15 and over. Individual data were collected on self-reported lifestyle habits and chronic co-morbidities, but were aggregated to the current 52 health districts and 9 provinces in the country. We used a Bayesian geo-additive mixed model based on Markov Chain Monte Carlo techniques to map the spatial distribution of hypertension at the province-level, accounting for individual risk factors. The overall prevalence of hypertension (blood pressure ≥140/90 mm Hg) was 25.1%. In multivariable Bayesian geo-additive regression analyses, men [odds ratio (OR) & 95% Credible Region (CR): 1.29 (1.14, 1.44)], coloured [1.20 (1.01, 1.42)], current smokers [1.14 (1.03, 1.27)] and current drinkers [1.14 (1.01, 1.27)] were consistently associated with higher prevalence of hypertension. In spatial analyses, a significantly higher prevalence of hypertension was found in provinces with higher poverty and income inequalities [Free State: 1.34 (1.14, 1.62); North West: 1.33 (1.12, 1.58)]. To our knowledge this was the first study, which attempted to estimate the spatial variation of predictors of hypertension at the province-level in South Africa, after accounting for individual risk factors. Findings suggest distinct spatial patterns in hypertension prevalence in South Africa, pointing to the independent role of socio-economic disparities at the province-level, beyond individual-level risk factors for hypertension in this setting.
- © 2012 by American Heart Association, Inc.