Racial/Ethnic Heterogeneity and Rural-Urban Disparity of COVID-19 Case Fatality Ratio in the USA: a Negative Binomial and GIS-Based Analysis

Abstract

The 2019 coronavirus disease (COVID-19) has exacerbated inequality in the United States of America (USA). Black, indigenous, and people of color (BIPOC) are disproportionately affected by the pandemic. This study examines determinants of COVID-19 case fatality ratio (CFR) based on publicly sourced data from January 1 to December 18, 2020, and sociodemographic and rural-urban continuum data from the US Census Bureau. Nonspatial negative binomial Poisson regression and geographically weighted Poisson regression were applied to estimate the global and local relationships between the CFR and predictors-rural-urban continuum, political inclination, and race/ethnicity in 2407 rural counties. The mean COVID-19 CFR among rural counties was 1.79 (standard deviation (SD) = 1.07; 95% CI 1.73-1.84) higher than the total US counties (M = 1.69, SD = 1.18; 95% CI: 1.65-1.73). Based on the global NB model, CFR was positively associated with counties classified as "completely rural" (incidence rate ratio (IRR) = 1.24; 95% CI: 1.12-1.39) and "mostly rural" (IRR = 1.26; 95% CI: 1.15-1.38) relative to "mostly urban" counties. Nonspatial regression indicates that COVID-19 CFR increases by a factor of 8.62, 5.87, 2.61, and 1.36 for one unit increase in county-level percent Blacks, Hispanics, American Indians, and Asian/Pacific Islanders, respectively. Local spatial regression shows CFR was significantly higher in rural counties with a higher share of BIPOC in the Northeast and Midwest regions, and political inclination predicted COVID-19 CFR in rural counties in the Midwest region. In conclusion, spatial and racial/ethnic disparities exist for COVID-19 CFR across the US rural counties, and findings from this study have implications for public health.

Keywords: COVID-19 severity; Disease severity; Political inclination; Racial/ethnic minorities; Rural-urban continuum; Spatial analysis.

Fig. 1

Pairwise comparisons of COVID-19 case fatality ratio by rural-urban continuum (note: each node shows the sample average rank of the rural-urban continuum)

Fig. 2

Racial/ethnic disparity in COVID-19 case fatality ratio in rural-urban counties (adjusted)

Fig. 3

Geographic distribution of case fatality ratio in rural counties and hotspots

Fig. 4

Racial/ethnic disparity in COVID-19 case fatality ratio in US rural counties (note: the model adjusted for population density, political inclination, and county-level household median income)

Fig. 5

Results of geographically weighted Poisson regression. a Predicted rates. b-e Coefficients of percent Black, indigenous, and people of color in rural counties. f Coefficient of percent share of Trump 2020 votes. g Deviance residual. h Condition number