COVID-19 cases and deaths in 3141 US counties as of 10 August 2020, by quintiles of Social Vulnerability Index
| Social Vulnerability Index | |||||
| First quintile | Second quintile | Third quintile | Fourth quintile | Fifth quintile | |
| (Least vulnerable) | (Most vulnerable) | ||||
| COVID-19 cases | |||||
| Total cases | 368 312 | 808 447 | 1 088 614 | 1 614 575 | 1 130 548 |
| Crude rate per 100 000; median (IQR) | 474 (279–786) | 594 (331–1008) | 670 (372–1272) | 1009 (485–1849) | 1816 (1020–2827) |
| Adjusted rate ratio (95% CI) | 1.0 (Ref.) | 1.24 (1.16 to 1.33) | 1.39 (1.30 to 1.49) | 1.76 (1.65 to 1.87) | 2.11 (1.97 to 2.26) |
| COVID-19 deaths | |||||
| Total deaths | 13 611 | 28 043 | 34 007 | 47 093 | 38 304 |
| Crude rate per 100,000; median (IQR) | 4 (0–15) | 8 (0–23) | 10 (0–27) | 15 (4–41) | 31 (12–68) |
| Adjusted rate ratio (95% CI) | 1.0 (Ref.) | 1.19 (1.09 to 1.30) | 1.22 (1.12 to 1.33) | 1.77 (1.63 to 1.92) | 2.42 (2.22 to 2.64) |
Rate ratios adjusted for US states as a fixed effect (to adjust for state-level confounding factors) in the Poisson regression models using the log of the population as an offset term, and a scale parameter, set as the Pearson χ2 statistic divided by the residual df, to address the issue of potential overdispersion. Data: US Centers for Disease Control and Prevention and USAFacts.
CI, confidence interval; df, degrees of freedom; IQR, interquartile range.