Table 2.
Overall association of county-level Social Vulnerability Index (IRR per 10 percentile increase) with incidence and death per capita of COVID-19 as of 6 March 2021
| Model 1* | Model 2† | Model 3‡ | ||||
| IRR (95% CI) | P value | IRR (95% CI) | P value | IRR (95% CI) | P value | |
| Incidence | ||||||
| Overall Social Vulnerability Index§ | 1.03 (1.03 to 1.04) | <0.001 | 1.02 (1.02 to 1.03) | <0.001 | 1.02 (1.02 to 1.03) | <0.001 |
| Socioeconomic status | 1.02 (1.02 to 1.03) | <0.001 | 1.02 (1.01 to 1.02) | <0.001 | 1.02 (1.01 to 1.02) | <0.001 |
| Minority status and language | 1.02 (1.01 to 1.02) | <0.001 | 1.02 (1.01 to 1.02) | <0.001 | 1.02 (1.01 to 1.02) | <0.001 |
| Housing type and transport | 1.01 (1.00 to 1.01) | 0.003 | 0.99 (0.99 to 1.00) | 0.07 | 0.99 (0.99 to 1.00) | 0.29 |
| Household composition and disability§ | 1.02 (1.01 to 1.02) | <0.001 | 1.01 (1.01 to 1.02) | <0.001 | 1.01 (1.01 to 1.02) | <0.001 |
| Death per capita | ||||||
| Overall Social Vulnerability Index§ | 1.07 (1.06 to 1.08) | <0.001 | 1.05 (1.04 to 1.06) | <0.001 | 1.04 (1.04 to 1.05) | <0.001 |
| Socioeconomic status | 1.07 (1.07 to 1.08) | <0.001 | 1.05 (1.04 to 1.06) | <0.001 | 1.05 (1.04 to 1.05) | <0.001 |
| Minority status and language | 1.03 (1.02 to 1.03) | <0.001 | 1.01 (1.00 to 1.02) | 0.003 | 1.01 (1.00 to 1.02) | 0.004 |
| Housing type and transport | 1.06 (1.05 to 1.06) | <0.001 | 1.05 (1.04 to 1.05) | <0.001 | 1.05 (1.04 to 1.05) | <0.001 |
| Household composition and disability§ | 1.04 (1.03 to 1.05) | <0.001 | 1.02 (1.01 to 1.02) | <0.001 | 1.02 (1.01 to 1.02) | <0.001 |
*Base model: adjusted for proportion of population aged ≥65 years and state-level COVID-19 testing.
†Base model+CMS average HCC score (proxy for comorbidities).
‡Base model+CMS average HCC score (proxy for comorbidities)+environmental factors including average daily temperature (degrees Fahrenheit), average daily precipitation and average particulate matter of diameter ≥2.5 μm.
§Proportion aged ≥65 years not included as a covariate for models for overall Social Vulnerability Index and household composition/disability because these indices contain the age variable.
CMS, Centers for Medicare and Medicaid Services; HCC, Hierarchical Condition Category; IRR, incidence rate ratio.