AHA Registry IDs Social Vulnerability as Risk Factor for COVID-19 Death

Patients hospitalized for COVID-19 in 2020 were at greater risk of in-hospital death and MACE if they lived in “socially vulnerable” US counties, data from the American Heart Association’s COVID-19 CVD Registry show.

The concept captures numerous factors like neighborhood socioeconomic status, multigenerational households, population density, language, and race/ethnicity, among others.

Fairly early in the pandemic, it became clear that Black and Hispanic individuals bore a disproportionate brunt of COVID-19 hospitalizations and deaths. Shabatun J. Islam, MD (Emory University School of Medicine, Atlanta, GA), lead author of the new paper, said that prior studies have tended to take a more of a big-picture, “ecological-level” approach to the question of how social determinants of health (SDOH) are linked to disparate outcomes.

For their study, published in Circulation: Cardiovascular Quality and Outcomes, “we wanted to know what was happening on an individual patient-to-patient level,” Islam told TCTMD. “We knew that there are large health disparities across most disease—cancer, cardiovascular disease—and we had a hunch given the political environment, etc, at that time [in the pandemic’s first wave] that individuals from vulnerable communities may have worse effects from COVID.” Moreover, she added, the COVID-19 CVD Registry enabled them to get a comprehensive look at what was happening at 107 hospitals across the US.

Islam said it came as a surprise that even after adjusting for patients’ comorbidities and presenting symptoms, neighborhood-level vulnerability continued to carry added risk.

COVID-19 CVD Registry

Using the COVID-19 CVD Registry, Islam and colleagues identified 16,939 patients hospitalized with COVID-19 between January and November 2020. They used the Social Vulnerability Index (SVI), which encompasses community-level socioeconomic status, household composition and disability, minority status and language, and housing type and transport, to characterize each patient’s place of residence at a county level.

Nearly 30% of the registry participants lived in areas with the highest levels of vulnerability, by SVI quartile. Compared with residents of the least-vulnerable areas, they tended to be younger (mean age 60.2 vs 62.3 years) and were more likely to be Black (36.7% vs 12.2%) and be insured through Medicaid (31.1% vs 23.0%; P < 0.001 for all). They also were more likely to be women (46.2% vs 42.1%; P = 0.008) and had a higher prevalence of comorbidities.

COVID-19 patients residing in the most-vulnerable areas were more likely to require mechanical ventilation (22.3% vs 18.3%), mechanical circulatory support (5.5% vs 3.9%), and vasopressor/inotrope support (9.3% vs 7.1%) but less likely to receive steroid treatment (34.0% vs 42.8%; P < 0.001 for all).

In-hospital mortality rates were 16.9% and 13.6%, respectively, for patients from most- versus least-vulnerable counties, while MACE rates were 20.2% and 16.1% (P < 0.001). The most vulnerable had higher rates of acute coronary syndrome (3.4% vs 2.4%; P = 0.01) and cardiac arrest (7.1% vs 2.3%; P < 0.001), though there were no differences seen for new-onset heart failure, stroke, myocarditis, ventricular arrhythmia, or cardiogenic shock.

Even with adjustment for age, sex, race/ethnicity, and insurance status, COVID-19 patients living in the most-vulnerable counties continued to have higher risks of in-hospital mortality (OR 1.25; 95% 1.03-1.53) and MACE (OR 1.26; 95% CI 1.05-1.50). The differences held steady, with nearly the same odds ratios, when clinical comorbidities and acuity of COVID-19 illness were added to the mix.

Among the various components of SVI, only socioeconomic status was linked to increased risk of in-hospital mortality.

Public Health and Daily Practice

The results emphasize the need for improvements in care of these patients at a health-system level, the researchers say. “More broadly, public health strategies that expand access to COVID-19 testing and increase vaccination rates, coupled with policies that encourage vulnerable populations to seek care (eg, paid leave when infected), rather than impeding access to care (eg, public charge rule), could help reduce inequities in COVID-19 outcomes.”

Understanding that context of the patient is very important, . . . because you can tailor what your recommendations are. Shabatun J. Islam

The study authors propose several pathways by which social vulnerability could be impacting risk. “Living in crowded households or working in front-line jobs increases the risk of exposure to SARS-CoV-2. These factors may also lead to a higher viral load among patients from socially vulnerable communities, a variable that was not captured in our study, but is associated with increased disease severity and mortality,” Islam and her coauthors note, going on to suggest that environmental stressors like higher pollution burden, humidity, and temperature may also contribute to worse outcomes.

Islam emphasized that clinicians, too, can integrate awareness of vulnerability into their day-to-day practice. “We have to be aware of where our patients live. A lot of patients we see may be unhoused, for example, [or] may be transiently housed, jumping from place to place, and that really impacts how much they are able to adhere to medical therapies as well as prevention,” she said, adding, “Understanding that context of the patient is very important, . . . because you can tailor what your recommendations are.”

She also stressed that physicians should be urging patients, especially those from socially vulnerable areas, to get vaccinated against COVID-19. Going forward, it will be “interesting to see what is happening in years two and three [of the pandemic] now that the vaccine is available, to see if there have been any changes,” said Islam.

An editorial accompanying the paper places its results, specific to COVID-19, into a larger context that extends beyond current circumstances.

It “is a stark reminder of the pervasive effects of social vulnerability on health and quality of life in underserved populations,” Safi U. Khan, MD (Houston Methodist DeBakey Heart and Vascular Institute, TX), and colleagues say. “To the same end, the COVID-19 pandemic has unmasked deeply rooted social and healthcare inequalities in our system.

“Therefore,” they continue, “it is imperative to realize that improvements in individual and population health cannot be achieved without acknowledging and alleviating SDOH at the community level via interventions to address unfavorable social circumstances of individuals and [at the] health-system level via integration of SDOH with clinical decision support systems to inform management for improving the healthcare.”