County-level sociodemographic risk factors linked to COVID-19 cases, mortality
Factors such as race and ethnicity, socioeconomic status, household members and environment were significantly associated with COVID-19 cases and mortality in United States counties, according to research published in JAMA Network Open.
“Our study found that people living in more socially disadvantaged counties were more likely to have COVID-19 infections and deaths,” Renuka Tipirneni, MD, MSc, a primary care physician in the department of internal medicine and health services researcher at the University of Michigan Medical School, told Healio Primary Care.
These areas, she added, need enhanced testing, treatments and vaccine distribution efforts to help curb COVID-19 transmission.
“In addition, health care, public health and social service organizations should target resources to socially disadvantaged communities that address social risk factors for COVID-19 — things like measures to prevent crowded housing and evictions, increased food distribution, and communicating about how to prevent the spread of COVID-19 in languages other than English.”
Tipirneni and colleagues conducted a cross-sectional study to evaluate the association between county-level sociodemographic risk factors and COVID-19 incidence. They used a mixed-effects binomial regression to assess this association. To evaluate COVID-19 mortality, they completed a zero-inflated negative binomial regression.
The researchers collected publicly available data on COVID-19 cases and mortality from January 20, 2020, through July 29, 2020.
They also collected sociodemographic data from publicly available datasets, including the CDC’s Social Vulnerability Index. The index includes four subindices on socioeconomic status — such as poverty and unemployment rates, income and education level — household composition and disability, racial/ethnic minority status and language and type of housing and transportation.
Counties’ SVIs were determined by adding indices and converting the sum into a percentile rank from 0 to 1, with higher scores indicating increased vulnerability to national disasters.
The researchers identified 4,289,283 COVID-19 cases and 147,074 COVID-19-related deaths in the United States by July 29, 2020.
Tipirneni and colleagues determined that each 0.1 increase in SVI score was associated with an increase of 14.3% in COVID-19 incidence rate (IRR = 1.14; 95% CI, 1.12-1.16), and an increase of 13.7% in COVID-19 mortalities. They noted an SVI score change from 0.5 to 0.6 was equivalent to 87 COVID-19 cases and three deaths per 100,000 people in a midsized metropolitan county.
Additionally, they found an increase of 0.1 in SVI score was associated with a weekly cumulative increase in COVID-19 incidence rate of 0.9% (IRR = 1.01; 95% CI, 1.01-1.01) and an increase in COVID-19 mortality of 0.5% (IRR = 1.01; 95% CI, 1.01-1.01).
Since the publication of their study, Tipirneni and colleagues have released county-level data on SVI, COVID-19 cases and COVID-19 mortality that public health officials can use to tailor interventions.
“With increased attention to activities ranging from prevention to treatment, inequalities in COVID-19 may be ameliorated over time,” Tipirneni said.
- Karmakar M, et al. JAMA Netw Open. 2021;doi:10.1001/jamanetworkopen.2020.36462.
- Newswise. County by county, study shows social inequality’s role in COVID-19’s toll. https://www.newswise.com/coronavirus/county-by-county-study-shows-social-inequality-s-role-in-covid-19-s-toll/?article_id=745178. Accessed February 1, 2021.