Yale University Study Finds Social Determinants of Health Surface in Large Hypertension Study

The doctor is checking the blood pressure of the patient.

Social determinants of health have emerged at the forefront of addressing health care system in trouble. Costs are skyrocketing and outcomes are not where they should be. These trends haven’t gone unnoticed from Yale School of Medicine researchers who recently studied data from a hypertension clinical trial data generated from 1994 to 2002. With thousands of patients, three hypertension drugs were evaluated.

Published in the Journal of American Heart Association, the Yale investigators assumed that with an eye toward the social determinants of health, they found that the location of care in a clinical trial can have an impact on the outcomes—regardless of protocol and associated treatment plan!

The Study

The Yale team studied the data of 13,000 clinical trial participants based throughout the United States. The objective; control for specific hypertension management and hopefully, understand how the clinical trial site and income levels of patients can correlate to individual patient outcomes in the study.

The Results

7.8% of the trial participants received their care in the lowest income sites and 37.6% receive care in the highest income sites. These disparities led to significantly varied outcomes. For example, patients in the lowest income sites were 25% more likely to die from any cause and 25% more prone to hospitalization or die because of heart failure.

Moreover, patients from the lower-income sites were more likely to develop end-stage renal disease (ESRD), and 30% less likely to receive common treatments for heart attack or chest pain, such as a procedure for opening up the blood vessels adjacent to the heart.

The results were of no surprise to the Yale team who already are aware of the impact of the social determinants of health.

Lead Investigator Discussion

Erica Spatz, associate professor, Yale School of Medicine noted “Typically in a randomized controlled trial where we try to equalize care across treatment arms and across clinical sites, we aim to isolate the effect of a medication to understand its efficacy” and she continued “While medications are the mainstay of hypertension control, there are other factors that we need to pay attention to that are impacting blood pressure control, and the ultimate outcomes we can about—heart disease, stroke, hospitalization, and longevity.”


Health begins in the home, the school, the workplace, one’s neighborhood and community. It is common knowledge, or we would hope so, that taking care of one’s self is the key to good health—eating healthy and staying active, for example—avoid smoking and excessive alcohol and of course, stay away from drugs.

But human health is also determined to a great extent by their social milieu, the socioeconomic factors and forces they are part of an embedded in—the neighborhood that they live in; the schools they attend the environmental conditions in their region. These makeup social determinants of health and can help explain why the actual conditions for which people grow up in help explain why some our healthier than others. One’s zip code in many ways can tell much about one’s access to good food, transportation, health care and exposure to toxic contamination.

Although a lot of this is common sense, it hasn’t been factored into health care in any kind of systematic way. Homelessness, for example, can be correlated to higher emergency department visits and hence costs and this trend caught the eye of payers—often public (Medicaid) minded analysts in the United States. This author has been part of a “whole person care” movement implementing databases to capture social determinants of health data for a deeper, more systematic analysis and hopefully, ultimately an understanding of how to improve health care outcomes (and reduce costs) in America.

It should be considered for designing clinical trial protocols (and by extension the entire trial). The Yale study results point to the need for more thought into the social determinants of health when designing randomized control trials, which seek to control all aspects of care to 100% test drug efficacy.

Lead Research/Investigator

Erica Spatz, Associate Professor