Abstract Body: Introduction
Areas where people disproportionately die at home from cardiovascular disease (CVD) are incompletely described. The United States (US) Centers for Disease Control and Prevention (CDC) developed the Social Vulnerability Index (SVI) using 16 US census measures clustered into four themes of vulnerability. The SVI and its themes may be utilized to score counties based on county-level social determinants of health. We conducted a county-level ecological study on the association of county SVI and its themes with CVD-related deaths occurring at home.

Method
We used 2016–2020 CDC Wide-ranging Online Data for Epidemiologic Research data on county-level CVD-related (ischemic heart disease, heart failure, stroke, and hypertension) deaths in persons ≥18 years of age, and location of death (home, etc.), available for 92.4% of 3,226 US counties. The SVI and its themes (socioeconomic status [theme 1], household composition & disability [theme 2], minority status & language [theme 3], and housing type & transportation [theme 4]) are scored from 0 to 1 (low to high vulnerability) based on their national percentile ranking. We grouped county-level SVI from 2018 into quartiles (Q1 [least] to Q4 [most vulnerable]). Due to overdispersion, we used negative binomial regression to estimate the likelihood of CVD-related deaths at home in Q4 vs Q1, offset by the total county CVD-related deaths. We reported rate ratios (RR [95% Confidence Interval], p-value).

Results
CVD-related home death rates increased in a stepwise manner from SVI Q1 to Q4 (Fig). For overall SVI, the likelihood of death at home was 15% higher in Q4 vs Q1 (RR 1.15 [1.12–1.18], p<0.0001). The greatest disparity was seen in theme 1, with Q4 vs Q1 having 27% higher likelihood of death at home (RR 1.27 [1.22–1.33], p<0.0001). For theme 2, there was no statistically significant difference in the likelihood of death at home in Q4 vs Q1 (RR 0.98 [0.95–1.01], p=0.36). For theme 3, Q4 vs Q1 had 6% higher likelihood of death at home (RR 1.06 [1.03–1.09], p<0.0001). For theme 4, Q4 vs Q1 had a 6% lower likelihood of death at home (RR 0.94 [0.91–0.97], p<0.001).

Conclusion
In US counties, higher social vulnerability was associated with a higher likelihood of CVD-related death at home, with the strength and direction of this association varying between the themes of vulnerability. SVI and its themes may be utilized to target interventions to improve access to hospital or hospice care.