Validating an index of community-level socioeconomic composition for global health research

Despite increasing recognition that community-level socioeconomic factors are critical to individual health outcomes globally, guidance on their measurement remains limited in resource-constrained settings. We outline the steps needed to develop and validate a theory-based, multidimensional index of community-level socioeconomic composition using information that is often available in global community-based studies. Our study population consisted of a cohort of 1822 children aged 7 to 9 years and their households in the Southern plains of Nepal. We conducted a principal components analysis of indicators describing human and social capital to construct a community socioeconomic composition index (CSCI) using census data for the 30 communities in which children resided. We validated the index by testing the theoretical prediction that residents of communities with higher capital would have an advantage in accruing more future capital (infrastructural and household assets) and achieving better health (child nutritional status). In ecological analysis, the CSCI was positively correlated with validation measures (r=.67, .85, .54, and .58 for community infrastructure index, household asset index, child height-for-age z-score, and child weight-for-age z-score, respectively). In multilevel analysis, +1SD of the CSCI was associated with + 0.14SD of the household asset index (p<.01). These results suggest that an exclusively census-based strategy to measure socioeconomic composition has construct validity in this setting. Our approach to measuring community-level socioeconomic composition may be feasibly reproduced in other resource-constrained settings where census data are available, potentially expanding the scope of place and health research globally.