Development and Validation of Household Asset-Based Socio-Economic Index — Results from SAGE4Health Study in Rural Malawi

Background

Understanding social drivers of HIV risk and vulnerability is essential in highly impacted countries such as Malawi (11% HIV rate). Effects of Socioeconomic status (SES) on HIV/AIDS have not been well studied in developing countries, leaving gaps in how to define, validate, and measure SES.  Rather than income/expenditure, literature suggests using asset-based variables as a more reliable measure to develop SES indices in low-income settings.

Methods

We conducted Principal Components Analyses (N=899) to generate a Social Economic Index from an array of household assets variables. We used baseline data from a non-equivalent control group effectiveness study (SAGE4Health) that examined pathways linking distal ecosocial factors to HIV vulnerability in rural Malawi. The index’s criterion-related validity was examined. Finally, we classified households into quintiles to represent SES gradient.

Results

The factor analysis revealed eight principal factors explaining 60% of the variance. The first component, explaining the largest variance proportion (20%), related to ownership and quality of housing stock, such as roof and floor types, and bed number. The second and third components included ownership and quality of livestock (i.e., improved dairy cows or work oxen) and radio and farming equipment (i.e., axes, sickles) ownership, respectively. The index demonstrated good criterion-related validity and was significantly associated with HIV vulnerability (e.g., food security).

Conclusions

The PCA generated robust asset-based proxy SES indices to differentiate SES status. Findings support the validity of our Malawi study index and suggest the utility of using the index for research on HIV vulnerability in rural sub-Saharan countries.