ABSTRACT
BackgroundThe COVID-19 pandemic adversely affected the socially vulnerable and minority communities in the U.S. initially, but the temporal trends during the year-long pandemic remain unknown. ObjectiveWe examined the temporal association between the county-level Social Vulnerability Index (SVI), a percentile-based measure of social vulnerability to disasters, its subcomponents and race/ethnic composition with COVID-19 incidence and mortality in the U.S. in the year starting in March 2020. MethodsCounties (n=3091) with [≥] 50 COVID-19 cases by March 6th, 2021 were included in the study. Associations between SVI (and its subcomponents) and county level racial composition with the incidence and death per capita were assessed by fitting a negative-binomial mixed-effects model. This model was also used to examine potential time varying associations between weekly number of cases/deaths and SVI or racial composition. Data was adjusted for percentage of population aged [≥]65 years, state level testing rate, comorbidities using the average Hierarchical Condition Category (HCC) score, and environmental factors including average fine particulate matter (PM2.5), temperature and precipitation. ResultsHigher SVI, indicative of greater social vulnerability, was independently associated with higher COVID-19 incidence (adjusted incidence rate ratio [IRR] per-10 percentile increase:1.02, (95% CI 1.02, 1.03, p<0.001), and death per capita (1.04, (95% CI 1.04, 1.05, p<0.001). SVI became an independent predictor of incidence starting from March 2020, but this association became weak or insignificant by the winter, a period that coincided with a sharp increase in infection rates and mortality, and when counties with higher proportion of White residents were disproportionately represented ("third wave"). By Spring of 2021, SVI was again a predictor of COVID-19 outcomes. Counties with greater proportion of Black residents also observed similar temporal trends COVID-19-related adverse outcomes. Counties with greater proportion of Hispanic residents had worse outcomes throughout the duration of the analysis. ConclusionExcept for the winter "third wave" when majority White communities had the highest incidence of cases, counties with greater social vulnerability and proportionately higher minority populations, experienced worse COVID-19 outcomes. Article Summary/Strengths & LimitationsO_LIExamined full 12 months of county-level data in the US delineating the temporal trends in the association between social vulnerability index and COVID-19 outcomes C_LIO_LIInvestigated COVID-19 outcomes in predominantly Black and Hispanic communities in comparison to White communities in the US C_LIO_LIAnalysis is ecological, descriptive, and on the county-level rather than on an individual level C_LIO_LIAnalysis adjusted for confounders including county level age [≥] 65, comorbidities, and environmental factors C_LIO_LIAnalysis limited to the US C_LI
ABSTRACT
ImportancePrior pandemics have disparately affected socially vulnerable communities. Whether regional variations in social vulnerability to disasters influence COVID-19 outcomes and incidence in the U.S. is unknown. ObjectiveTo examine the association of Social Vulnerability Index (SVI), a percentile-based measure of county-level social vulnerability to disasters, and its sub-components (socioeconomic status, household composition, minority status, and housing type/transportation accessibility) with the case fatality rate (CFR) and incidence of COVID-19. DesignEcological study of counties with at least 50 confirmed COVID-19 cases as of April 4th, 2020. Generalized linear mixed-effects models with state-level clustering were applied to estimate county-level associations of overall SVI and its sub-component scores with COVID-19 CFR (deaths/100 cases) and incidence (cases/1000 population), adjusting for population percentage aged [≥]65 years, and for comorbidities using the average Hierarchical Condition Category (HCC) score. Counties with high SVI ([≥]median) and high CFR ([≥]median) were identified. SettingPopulation-based study of U.S. county-level data. ParticipantsU.S. counties with at least 50 confirmed COVID-19 cases. Main outcomes and measuresCOVID-19 CFR and incidence. ResultsData from 433 counties including 283,256 cases and 6,644 deaths were analyzed. Median SVI was 0.46 [Range: 0.01-1.00], and median CFR and incidence were 1.9% [Range: 0-13.3] and 1.2 per 1000 people [Range: 0.6-38.8], respectively. Higher SVI, indicative of greater social vulnerability, was associated with higher CFR (RR: 1.19 [1.05, 1.34], p=0.005, per-1 unit increase), an association that strengthened after adjustment for age[≥]65 years and comorbidities (RR: 1.63 [1.38, 1.91], p<0.001), and was further confirmed in a sensitivity analysis limited to six states with the highest testing levels. Although the association between overall SVI and COVID-19 incidence was not significant, the SVI sub-components of socioeconomic status and minority status were both predictors of higher incidence and CFR. A combination of high SVI ([≥]0.46) and high adjusted CFR ([≥]2.3%) was observed in 28.9% of counties. Conclusions and RelevanceSocial vulnerability is associated with higher COVID-19 case fatality. High social vulnerability and CFR coexist in more than 1 in 4 U.S. counties. These counties should be targeted by public policy interventions to help alleviate the pandemic burden on the most vulnerable population. KEY POINTSO_ST_ABSQuestionC_ST_ABSIs county-level social vulnerability to disasters associated with the case fatality rate (CFR) and incidence of SARS-CoV-2 infection during the COVID-19 pandemic in the U.S.? FindingsEach unit increase in county-level social vulnerability, measured using the Social Vulnerability Index (SVI), was associated with a 63% higher CFR after adjusting for age and comorbidities. Both CFR and incidence of COVID-19 were significantly higher in counties with lower socio-economic status and higher proportion of minority populations. MeaningU.S. counties with higher social vulnerability are experiencing greater mortality rates during the COVID-19 pandemic.
