Socio-economic status (SES) indices are increasingly being used to characterise inequity, with the assumption that SES indices are reliable. However, the accuracy of such SES indices is questionable if they are unreliable. We examined the inter-rater and test-retest reliability of a range of indicators commonly used to generate SES indices, as well as reliability of SES indices. Results from research in southeast Nigeria showed considerable variation, with some indicators having only low to moderate reliability coefficients (0.25-0.77). Inter-rater and test-retest reliability of SES indices was 0.63 in both cases. Many households were mis-classified because of the unreliable SES indices. Analyses of the distribution of resources based on such indicators could lead to inaccuracies in benefit incidence estimates and policy decisions based on low-to moderately reliable SES indicators and indices could worsen equity in access to and use of resources. There should be greater rigour in conceptualising as well as undertaking SES measurements.
Malaria Journal (2004) 3 (6) [doi: 10.1186/1475-2875-3-6]