Then And Now: Umbrella Variables Mask Temporal Mechanisms Of Structural Racism In US Urban Environments.

Introduction: Racist urban development policies and capitalist municipal management have continued the cycle of poverty experienced by many in the US. Modeling this disadvantage often relies on composite, or "umbrella", socioeconomic variables. We argue that this approach obfuscates the temporal nature of social determinants. We propose organizing downstream consequences of structural racism by exposure duration-historical disenfranchisement and contemporary disadvantage-to assess their differential effect on excess all-cause mortality in an U.S. urban environment during the COVID-19 pandemic.

Methods: ZIP-code tabulation area (ZCTA) 2020 and 2021 demographics were used to create an historical disenfranchisement index, a contemporary disadvantage index, and combined index (our proxy for a "umbrella" variable) for 210 ZCTAs in the Kansas City Metropolitan Area. Indices were dichotomized into "above" and "below" average, as well as a quadrant matrix index categorizing ZCTAs by "above average" in both, one index only, or neither. General linear models assessed the relationship between the indices and excess all-cause mortality. Model fit was compared by AIC.

Results: Across all models, ZCTAs that experienced above average structural racism had significantly greater excess all-cause mortality than those with below average structural racism markers. The quadrant model (AIC = 3441) performed significantly better than the combined index (AIC = 3468.3) with a reduction in AIC of 27.2.

Conclusion: Composite metrics of disadvantage may mask important distinctions in how mechanisms of structural racism are associated with health outcomes. This analysis provides support for place-based, historically sensitive health research.