Table 3.

Overall association of county-level race/ethnic composition (IRR per 10% increase) with incidence and case fatality rate 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
White	0.99 (0.98 to 0.99)	<0.001	1.00 (1.00 to 1.01)	0.45	1.01 (1.00 to 1.01)	0.20
Black	1.01 (0.99 to 1.01)	0.24	0.99 (0.98 to 1.00)	0.01	0.99 (0.98 to 1.00)	0.01
Hispanic	1.06 (1.05 to 1.07)	<0.001	1.06 (1.05 to 1.07)	<0.001	1.07 (1.05 to 1.08)	<0.001
Death per capita
White	0.94 (0.93 to 1.00)	<0.001	0.99 (0.97 to 1.00)	0.05	0.99 (0.97 to 1.00)	0.05
Black	1.06 (1.04 to 1.08)	<0.001	1.00 (0.99 to 1.02)	0.91	1.00 (0.99 to 1.02)	0.85
Hispanic	1.10 (1.08 to 1.11)	<0.001	1.067 (1.049 to 1.085)	<0.001	1.07 (1.05 to 1.08)	<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.

CMS, Centers for Medicare and Medicaid Services; HCC, Hierarchical Condition Category; IRR, incidence rate ratio.