The Effect of Social Vulnerability on COVID-19 Outcomes in Louisiana

Background and Purpose: Early on in the COVID-19 pandemic, it quickly became apparent that, beyond individual-level risk, entire communities appeared more vulnerable to deaths from COVID-19, especially those with a higher concentration of African Americans and low household income. As such, there is a growing need to identify vulnerable communities. Social vulnerability indices attempt to codify a community's level of vulnerability to poor disaster outcomes by factoring socioeconomic characteristics into one score or a subset of scores. In March 2021, the Louisiana Dept of Health (LDH) announced their intent use the Social Vulnerability Index (SVI) developed by the CDC to focus vaccination education and dissemination efforts on communities most in need.

Few studies have examined the relationship between social vulnerability and COVID-19 as of one year into the pandemic. There have been no studies examining the association between COVID-19 testing or vaccination rates and social vulnerability. This study aimed to examine social vulnerability's effects on COVID-19 outcomes and Louisiana's response, including COVID-19 incidence, deaths, testing, and vaccinations, a full year into the pandemic.

Methods: Data and samples: I used the publicly available CDC 2018 SVI data sets for Louisiana at the parish (county) and census tract levels, which are based on American Community Survey (ACS) 2014-2018 5-year estimates. COVID-19 outcomes were retrieved from the LDH Coronavirus Dashboard. The sample included 1,115 Louisiana census tracts (examining cases, tests, and vaccinations) and 64 Louisiana parishes (examining deaths, which were not available at census tract level).

Analysis: The four COVID-19 outcomes (cases, deaths, tests, vaccinations) were adjusted for population size by calculating per capita variables (10,000 residents). Three regression models were estimated per COVID-19 outcome: Model 1 examined the COVID-19 outcome and overall SVI, Model 2 examined the COVID-19 outcome and each of the four SVI themes, and Model 3 examined the COVID-19 outcome and the 15 variables contained in the CDC SVI. Population density was included as a control variable in all models, and COVID-19 incidence was included in models examining tests and deaths.

Results: Overall social vulnerability was related to higher rates of COVID-19 deaths and tests and lower vaccination rates. However, it did not significantly predict COVID-19 incidence. When controlling for all variables, COVID-19 incidence was significantly related to the percentage of the population that were below poverty, disabled, older adults, children, and single-parent households. Deaths were also significantly related to percentage of minority population and crowded housing.

Conclusions and Implications: The SVI is a valuable tool in predicting COVID-19-related outcomes. Localized studies are more useful to understand the specific vulnerabilities that are the most influential in a community. This study hopes to be useful to social workers, public health workers, communities, and policymakers in determining their communities’ vulnerability to COVID-19 outcomes, as well as future pandemics. It also hopes to shed light on how resources, such as testing and vaccines, were distributed to communities along differing levels of vulnerability.