Assessing household wealth in health studies in developing countries: a comparison of participatory wealth ranking and survey techniques from rural South Africa

BACKGROUND: Accurate tools for assessing household wealth are essential for many health studies in developing countries. Household survey and participatory wealth ranking (PWR) are two approaches to generate data for this purpose. METHODS: A household survey and PWR were conducted among eight villages in rural South Africa. We developed three indicators of household wealth using the data. One indicator used PWR data only, one used principal components analysis to combine data from the survey, while the final indicator used survey data combined in a manner informed by the PWR. We assessed internal consistency of the indices and assessed their level of agreement in ranking household wealth. RESULTS: Food security, asset ownership, housing quality and employment were important indicators of household wealth. PWR, consisting of three independent rankings of 9671 households, showed a high level of internal consistency (intraclass correlation coefficient 0.81, 95% CI 0.79-0.82). Data on 1429 households were available from all three techniques. There was moderate agreement in ranking households into wealth tertiles between the two indicators based on survey data (spearman rho = 0.69, kappa = 0.43), but only limited agreement between these techniques and the PWR data (spearman rho = 0.38 and 0.31, kappa = 0.20 and 0.17). CONCLUSION: Both PWR and household survey can provide a rapid assessment of household wealth. Each technique had strengths and weaknesses. Reasons for differences might include data inaccuracies or limitations in the methods by which information was weighted. Alternatively, the techniques may measure different things. More research is needed to increase the validity of measures of socioeconomic position used in health studies in developing countries

Wealthy and healthy? New evidence on the relationship between wealth and HIV vulnerability in Tanzania

Using AIS/DHS data for Tanzania in 2003-4, 2007-8 and 2011-12 and borrowing from the methodology used in Parkhurst (2010) we analyse the changing relationship between wealth and HIV prevalence in Tanzania. Findings are tabulated, graphed and discussed. We find the relationship is multifaceted and dynamic: women are disproportionately affected in all wealth quintiles and experience a stronger ‘wealth effect’; some groups experience an increase in prevalence even as population prevalence declines. Relative wealth and poverty are associated with increased prevalence, suggesting that structural drivers create a variety of risk situations – as well as protective factors – affecting different groups. We also consider data on testing refusals: wealthier men were consistently more likely to decline testing. Continuing to unpack this complex and shifting relationship is necessary in order to fully understand the structural drivers of HIV transmission and access of testing services, enabling the formulation of appropriate policy responses