Number, Not Just Type, of Social Determinants Impacts Cardiovascular Health

December 10, 2020
Jared Kaltwasser

The idea that social factors affect health outcomes is not new, but new research suggests total number of social determinants of health is a valuable proxy for coronary heart disease risk.

Social determinants of health (SDOH) have long been a concern of the public health community, but a new study suggests the number, not just the type, of social determinants can be an important risk factor for coronary heart disease (CHD).

Writing in the journal Circulation, corresponding author Monika M. Safford, M.D., of Weill Cornell Medicine, and colleagues noted that investigators have developed indices of social deprivation that can be used by physicians to better understand SDOH-based risk.

“However, indices often include characteristics of small geographic areas and may be difficult for clinicians to construct and interpret for their patients during a clinical encounter,” Safford and colleagues wrote.

In light of this difficulty, Safford and colleagues sought to investigate a simpler way of quantifying SDOH risk, focusing not on individual types of determinants, but rather on the total number of them.

The investigators looked at data from the prospective longitudinal Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a national study that from 2003-2007 enrolled 30,000 Americans initially with the goal of tracking stroke risk. The study included SDOH data, making it a valuable dataset for Safford and colleagues’ investigation.

The team focused on social factors which have been associated with CHD outcomes and which can easily be ascertained by physicians.

“Education, where they live, whether the area is in a physician shortage area, which state you’re in, how isolated they are socially, their race/ethnicity, their health insurance—all these are recommended parts of the social history,” Safford told Managed Healthcare Executive®. “So, in a nutshell, the information we included in the study should be routinely collected as part of high-quality healthcare, albeit indirectly for annual household income.”

The investigators’ analysis cohort yielded 22,152 patients in the REGARDS dataset who did not have CHD at baseline. A majority (58.8%) were women, and 42.0% were black. The cohort was fairly evenly spread in terms of number of SDOH: 20.6% had no SDOH, 30.6% had a single SDOH, 23% had two, and 25.8% had at least three.

At a median follow-up of 10.7 years, 463 fatal incident CHD events were reported, and 932 nonfatal myocardial infarction events were reported.

Adjusted for age, the data showed a clear increase in risk as the number of social determinants increased. For instance, the incidence of fatal CHD per 1,000 person-years was 1.3 for people with 0 SDOH, but 2.86 for people with three or more SDOH. For nonfatal MI, the rate per 1,000 person-years was 3.91 among people with no SDOH, but 5.44 among people with at least two SDOH.

A person with three or more SDOH had a 3 crude HR and a 1.67 fully adjusted HR for fatal incident CHD. For nonfatal MI, the crude HR of a person with two or more SDOH was 1.57 and the adjusted HR was 1.14.

Safford and colleagues concluded that targeted interventions could make a meaningful difference for many patients with SDOH and suggested that population health managers could play a crucial role in these cases.

“In conclusion, a simple count of widely available SDOH may be a novel approach to identify individuals at high risk of incident CHD events that could be used in the course of clinical care,” they said.