Purpose: To explore how race and residential zip codes' socioeconomic index (SES) influenced COVID-19 testing rates in St. Louis during the early and peak phases of the pandemic.
Method: An ecological study was conducted using COVID-19 testing data from March to November 2020 in St. Louis City. The study included 16,915 individual tests from 30 residential zip codes.
Results: The overall testing rate in St. Louis was 303.97 per 10,000 population. Testing rates among Blacks, Whites, American Indian/Alaskan Natives, and Asians were 374.26, 247.77, 360.63, and 242.41 per 10,000, respectively. Higher testing rates were observed in low and middle SES zip codes compared to high SES zip codes. Adjusted for SES, testing rates were 1.68% higher among Blacks and 0.43% higher among American Indian/Alaskan Natives compared to Whites, and 0.033% lower among Asians. Geographical mapping showed higher testing rates in the inner core and lower rates in the periphery of St. Louis.
Conclusion: Race and SES influence testing rates. Areas with low testing rates should be targeted for intervention in St. Louis.