Should health studies measure wealth? A systematic review

Background: Health researchers rarely measure accumulated wealth to reflect socioeconomic status/ position (SES). In order to determine whether health research should more frequently include measures of wealth, this study assessed the relationship between wealth and health. Methods: Studies published between 1990 to 2006 were systematically reviewed. Included studies used wealth and at least one other SES measure as independent variables, and a health-related dependent variable. Results: Twenty-nine studies met inclusion criteria. Measures of wealth varied greatly. In most studies, greater wealth was associated with better health, even after adjusting for other SES measures. The findings appeared most consistent when using detailed wealth measures on specific assets and debts, rather than a single question. Adjusting for wealth generally decreased observed racial/ethnic disparities in health. Conclusions: Health studies should include wealth as an important SES indicator. Failure to measure wealth may result in under-estimating the contribution of SES to health, such as when studying the etiology of racial/ethnic disparities. Validation is needed for simpler approaches to measuring wealth that would be feasible in health studies.