Shifting emergency department utilization patterns among vulnerable populations during the COVID-19 pandemic

The COVID-19 pandemic impacted nearly every aspect of modern society. The medical industry was underprepared for the pandemic-related shifts in emergency department (ED) utilization, which significantly altered healthcare access for millions of Americans, particularly those within socially vulnerable groups. To provide understanding of how the pandemic caused shifts in ED visit severity through the lens of the social determinants of health is critical for better informing healthcare policy decisions when we’re facing the next pandemic or disease-related disaster. A retrospective, observational cohort study spanning 2 years before and after the first COVID-19 case was declared in Tennessee on March 8, 2020. Data from the University of Tennessee Health Science Center’s Research Enterprise Data Warehouse (rEDW) was collected for over 1 million ED visits, each of which was assigned a visit reason by the NYU-EDA. Independent variables included age, race, gender, Charlson Comorbidity Index (CCI), healthcare system, and both community- and individual-level social vulnerability indicators. Patients were considered vulnerable by either a documented Z-code or a CDC Social Vulnerability Index (SVI) below the 10th percentile. Our final analysis included 654,232 patients and 1,432,571 ED visits across the pre- and post- periods; 70,698 (11%) were considered socially vulnerable individuals. The average number of visits was 1.95 over two years, compared to 1.64 average visits for individuals in the two years following this date (95% CI = 0.29983, 0.32417). The steepest decline occurred near the beginning of the pandemic. The difference in means was 0.32 (95% CI: 0.300, 0.324). The mean ED visit per socially vulnerable patient saw a statistically significant decline after COVID-19 began, where the average visits decreased from 6.84 pre-COVID to 4.96 post-COVID (95% CI = 0.120, 0.180, 1.245, 2.515). However, vulnerable populations had the highest average visits both before and after the pandemic’s onset. By quantifying ED utilization during the 2-year period before and after the pandemic, we revealed significant shifts in visit frequency and severity across different demographics and social vulnerability groups.